header/logo A friendly caricature of Clausewitz by David Levine


by Christopher Bassford


Version 8 MAR 2016

Since the close of the Vietnam War, the ideas expounded by the Prussian military theorist Carl von Clausewitz (1780-1831) have come—very often in twisted, garbled, or mutated form—to thoroughly permeate American military writing (doctrinal, theoretical, and historical). His book On War (published posthumously in Prussia as Vom Kriege in 1832), was adopted as a key text at the Naval War College in 1976, the Air War College in 1978, and the Army War College in 1981. It has always been central at the U.S. Army's School for Advanced Military Studies at Leavenworth (founded in 1983). The U.S. Marine Corps's brilliant little philosophical field manual FMFM 1: Warfighting (1989) was essentially a distillation of On War (with a heavy maneuverist flavoring from Sun Tzu), and the more recent Marine Corps Doctrinal Publications (MCDPs, c.1997) equally reflect many of Clausewitz's basic concepts.*2

This is not the first time Clausewitz has been in fashion. Indeed, On War has been the bible of many thoughtful soldiers ever since Field Marshal Helmuth von Moltke attributed to its guidance his stunning victories in the wars of German unification (1864, 1866, 1870-71). Nor is it the first time that individual American soldiers and military thinkers have been attracted by his ideas: George Patton, Albert Wedemeyer, and—especially—Dwight Eisenhower were intensely interested in what he had to say.

It is, however, the first time that the American armed forces as institutions have turned to Clausewitz. While the philosopher had insisted that war was "simply the expression of politics by other means," the traditional attitude of American soldiers had been that "politics and strategy are radically and fundamentally things apart. Strategy begins where politics end. All that soldiers ask is that once the policy is settled, strategy and command shall be regarded as being in a sphere apart from politics."*3

The sudden acceptability of Clausewitz in the wake of Vietnam is not difficult to account for, for among the major military theorists only Clausewitz seriously struggled with the sort of dilemma that American military leaders faced in the aftermath of their defeat there. Clearly, in what had come to be scathingly called a "political war," the political and military components of the American war effort had come unstuck. It ran against the grain of America's military men to publicly criticize elected civilian leaders, but it was just as difficult to take the blame upon themselves. Clausewitz's analysis could not have been more relevant:

The more powerful and inspiring the motives for war,... the more closely will the military aims and the political objects of war coincide, and the more military and less political will war appear to be. On the other hand, the less intense the motives, the less will the military element's natural tendency to violence coincide with political directives. As a result, war will be driven further from its natural course, the political object will be more and more at variance with the aim of ideal war, and the conflict will seem increasingly political in character.*4

When people talk, as they often do, about harmful political influence on the management of war, they are not really saying what they mean. Their quarrel should be with the policy itself, not with its influence. If the policy is right—that is, successful—any intentional effect it has on the conduct of the war can only be to the good. If it has the opposite effect the policy itself is wrong.*5

Many of America's soldiers found unacceptable any suggestion that they had failed on the battlefield, but they were willing to admit that policy had been badly made and that they had misunderstood their role in making it. They believed that, by clarifying the interplay among the armed forces, government, and people and by clearly describing the two sides of the civil-military relationship, Clausewitz offered a way out of this dilemma and into the future. This is why versions of Clausewitz's ideas underlie the most influential statements of the military "lessons learned" from the Vietnam debacle: Colonel Harry Summers's seminal On Strategy: A Critical Analysis of the Vietnam War and the "Weinberger doctrine," first expressed by Secretary of Defense Caspar Weinberger in 1984.

With the West victorious in the Cold War and the superb showing of the American military in the 1990-91 Gulf War, some of the steam went out of the American military reform movement. There was a natural tendency for soldiers not only to suggest that these victories showed that the problems had been fixed but to imply that there really hadn't been much of a problem in the first place. Accordingly, the study of Clausewitz started to wane somewhat and all the usual arguments for his obsolescence resurfaced. However, the failure of much of the new, "non-Clausewitzian" military thinking in the wake of American offensives after the atrocity of 11 September 2001 then led to the customary re-revisions. Clausewitz is very much back in style—with new attention to his thoughts on "people's war," the inherent power of the defense, etc. But this new fashionability applies mostly to civilian and military scholars, not to America's military institutions. The latter tend to labor under the delusion that Clausewitz's ideas on war are not relevant to topics like LIC, COIN, and insurgency (a notion that would have puzzled practical insurgent warfighters like Mao and Giap—both strong proponents for the study of Clausewitz).

Such recent developments help to justify the study of Clausewitz to the contemporary American security professional, but there are far deeper reasons to read his works. Clausewitz was much more than a strategist: he was a historian and a historical philosopher, a political theorist, and a practical soldier of wide experience. His thought runs like a subterranean river through all modern military thought. We find it in the Marxists, Leninists, and Mao Zedong, in Colin Powell, among political scientists like Samuel Huntington and Robert Osgood, in the writings of military historians like Hans Delbrück and of navalists like Sir Julian Corbett, as well as in the doctrines of AirLand Battle and Warfighting. As the German general Jacob Meckel said well before World War One, "everyone who nowadays either makes or teaches war in a modern sense, bases himself upon Clausewitz, even if he is not conscious of it."*6 This is even truer now than it was then.

National security professionals are therefore obliged to become familiar with the concepts of this most influential of military thinkers. Given the admitted difficulties of digesting Clausewitz's massive and sometimes overpowering tome, however, most readers evidently feel compelled to look for some more cost-effective method of accessing his insights. The bibliographies of books on military history and theory are full of works that seek to explain or condense Clausewitz's theories. Some are more successful than others. A few are brilliant. Nonetheless, a word of warning is necessary here: No second-hand description of Clausewitz's ideas is really acceptable as a substitute for his own work, for none can capture the richness and complexity of his great theoretical work, On War. Its form and method are at least as important as its content. Reducing On War to a set of "bullet points" deprives the reader of its principal value—i.e., sustained contact with a brilliant mind. Even honest attempts to condense or capsulize it (including the one you have before you at this moment) are distorted by the impact of transient contemporary events, concerns, and concepts and by the idiosyncracies and personal interpretations of their writers.*7 And a great many treatments of Clausewitz have not been honest, being written by competitors, propagandists, or arm-chair strategists with no practical understanding of war.

The present article provides a short survey of the man and his works, with an emphasis on those that have been translated into English. The discussion is molded by an acute awareness of the widespread confusion regarding both the man and his concepts. Hopefully, it will aid the reader in understanding and evaluating the many references made to Clausewitz in military literature. Quotations from On War given in this section are in most cases taken from the sometimes-sloppy 1976/1984 Howard/Paret translation, since that is the version most accessible to most readers. For the most accurate rendering of his prose, however, serious readers should consult the 1943 American translation by Otto Jolle Matthijs Jolles.

A Short Biography

Clausewitz's personality has been treated in a great many different ways. To the British military historian Michael Howard he was a "soldier's soldier" who wrote a practical military philosophy aimed at practical military men. Peter Paret, a German emigré to America who emerged as one of the most prominent of contemporary Clausewitz scholars, presents him as a brilliant but somewhat dry intellectual. Clausewitz's detractors have portrayed him as a bloodthirsty military dilettante, while generations of bored soldier-students in Germany as well as Britain and America have treated him as a stuffy old pedant, author of a dry and tiresome tome best left to college professors.

There are also many myths concerning his personal life and career that have obscured his actual character. Many of these myths originated in historians' misreadings of his loving, ambitious wife's letters to prominent friends reporting his sudden death. These letters were driven by her own heartbreak and bitterness.

What Marie could not foresee is how these lines would turn into a notoriously cartoonish image plaguing the perception of the military theorist's personality and lifework until this day. As Peter Paret observes, the letter to Elise von Bernstorff [the wife of Prussia's foreign minister] almost singlehandedly shaped the notion of Clausewitz as a depressed scholar, angry at the world that never recognized him. In the text, Marie mixed in her own disappointment that Carl had not achieved the higher political post that she dearly desired but, as their correspondence in 1831 has revealed, he was less eager to assume. Marie had seen his theoretical work not as a parallel intellectual endeavor but as a stepping-stone toward greater influence and an illustrious career. As she wrote [to him] in 1831, his country needed him for both Rat und Tat ("words and deeds"). Marie had also suggested, or maybe even gently pushed for, making On War public in his lifetime [which Clausewitz himself resisted]. In his own correspondence, Carl remained rather realistic about his place in history and, more importantly, somber about the limits of [his] political influence. Robbed of the opportunity one day to see her beloved husband in the midst of European affairs, Marie was the one truly depressed.*5.1

In fact, Clausewitz was a complex man both of action and of thought, and he left a complex legacy by no means easy to describe. Sensitive, shy, and bookish by nature, he could also be passionate in his politics, his love for Marie, and his longing for military glory. Frequently in combat, he regularly displayed coolness and physical courage. He was untouched by scandal in his personal life. His intellectual integrity was remarkable: he was ruthless in his examination of any idea, including his own. His keen analytical intelligence was accompanied, perhaps unavoidably, by a certain intellectual arrogance. The latter quality is amply demonstrated by the many sarcastic comments that appear in On War. Such characteristics may account for the fact that, while he rose rapidly to high rank in the Prussian service, he usually served in important staff positions rather than in command. This fact can be misleading, however: Staff officers occupy a rather more exalted place in the German military tradition than in the Anglo-American. In any case, Clausewitz's assignments from 1802 onwards gave him a front-row seat near the center of military-political events.

Carl Philipp Gottfried von Clausewitz was born near Magdeburg on 1 June or 1 July 1780. Although the name has been alleged by some writers to have had Polish origins, the family was German and patriotically Prussian. Despite their pretensions to nobility, however, the Clausewitzs were in fact of middle-class origins (though Carl did not know that). The elder Clausewitz had obtained a commission in the army of Frederick the Great but was retired during Frederick's purge of non-noble officers after the Seven Years War (1756-63). On the basis of Carl and his brothers' achievements, the family's nobility was confirmed without any hesitation by King Friedrich Wilhelm III in 1827. It may have caused him some personal frustration in his romance with the high-born Countess Marie von Brühl (whose mother—herself of middle-class English origins—long resisted their union), but any ambiguity in Clausewitz's social position does not appear to have blocked his military advancement.

Young Clausewitz (c.1807?)Clausewitz entered the Prussian army as a cadet at the age of twelve; he first saw combat (in a guerrilla-style campaign against revolutionaries in France) at thirteen. After Prussia withdrew from the wars of the French Revolution in 1795, he spent five years in boring garrison duties. There, he applied himself to his own education. Beyond strictly military subjects, Clausewitz would develop a wide-ranging set of interests in art, science, and education (especially later, under the influence of Marie). All of these interests would have an impact on his military-philosophical work. So successful were his efforts that in 1801 he was able to gain admission to the Institute for Young Officers in Berlin, which would eventually evolve into the famous Kriegsakademie. He quickly came to the attention of the new director, Gerhard von Scharnhorst, a key figure in the Prussian state during the upheavals of the Napoleonic wars and Chief of the General Staff in 1806.*8 Impressed by Clausewitz's ability, Scharnhorst was to become his sponsor, mentor, and close friend.*9 Clausewitz graduated at the top of his class in 1803 and was rewarded with the position of military adjutant to the young Prince August. This brought him into close contact with the royal family.

Many of Clausewitz's basic historical, political, and military views derived from the influence of Scharnhorst and other Prussian military reformers. In broad terms, their argument was that the French Revolution had achieved its astounding successes because it had tapped the energies of the French people. If the Prussian state was to survive, much less prosper, it had to do the same. This would require sweeping social and political reforms in the Prussian state and army, both of which had dry-rotted under the successors of Frederick the Great. Gerhard von ScharnhorstClausewitz's works therefore reflect a strong impulse towards social and military reform. However, neither he nor his mentors desired a social or political revolution, only such changes as were necessary to preserve Prussia's independence and power. This political position made him suspect to both conservatives and revolutionaries. His "insistence on what would one day be called `the primacy of foreign policy' set him at odds with those liberals and radicals who believed constitutional government was a political goal surpassing all others" (though he was in fact attracted by the British constitutional model). "It also made his point of view anathema to those [of the traditional ruling classes] who considered the preservation of the social hierarchy an objective rivaling the safety of the state."*10 Many subsequent writers have tried to cast Clausewitz as a political hero or villain in order to serve their own political agendas, but trying to place Clausewitz and his theories somewhere on an anachronistic left-right political spectrum is a futile exercise. His politics can only be understood with reference to the specific situation of Prussia in the Revolutionary and Napoleonic periods and in the post-war era of conservative reaction.*11

Alarmed at the devastating French victories over Austria and Russia in 1805, Prussia mobilized for war in 1806. Confident in the legacy of Frederick the Great, Captain Clausewitz and most other Prussian officers looked forward to a struggle with France. The timing and the implementation of Prussian mobilization were poor, however, and the nation was ill-prepared psychologically. The Prussian forces were shattered in humiliating defeats in battles at Jena and Auerstedt. Two weeks later, covering the retreat of what remained of the Prussian army, Clausewitz and Prince August were captured. In the peace settlement, Prussia lost half of its population and territory and became an occupied French satellite.

Map, Prussia

Prussia before Jena/Auerstadt (1805)

Map, Prussia, post-1807

Prussia after its defeat by Napoleon

NOTE: Prussia is the territory in purple. Note that before the Battles of Jena-Auerstadt Prussia consisted of many discontiguous territories, most of which were taken away in the peace settlement. In the left-hand map, the heavy black border marks the extent of the Holy Roman Empire, to which, oddly, only parts of Prussia belonged. Napoleon dissolved the Empire in 1806, replacing it with a new "Confederation of the Rhine" that excluded both Prussia and Austria. (Maps from Centennia, the historical mapping program.)

Defeat was both a shock and an eye-opener for Clausewitz. He recorded his impressions, both of the war and of the dismal socio-political condition of Prussia, in several short articles. Later (in the 1820s), he composed a detailed critique of 1806 Prussia—so incisive that it could not be published in Germany until the 1880s—called "Observations on Prussia in its Great Catastrophe."*12

When he returned from a comfortable and educational internment in France in 1808, he joined energetically with Scharnhorst and other members of the reform movement, helping to restructure both Prussian society and the army in preparation for what he felt to be an inevitable new struggle with the French. His duties included planning for a national insurrection against the French occupation, an enterprise that would involve a "people's war" (along the lines of the brutal guerrilla struggle in Spain) in conjunction with operations by the much-reduced Prussian army. His enthusiasm for active resistance to the French was not, however, shared by the King, who was more concerned with maintaining his position in the much-reduced Prussian state than with any patriotic crusade. Major Clausewitz's disillusionment reached a peak when occupied Prussia agreed to provide an army corps to Napoleon to assist in the 1812 invasion of Russia. Along with about thirty other officers, he resigned from Prussian service.*13 He then accepted a commission in the Russian army in order to continue the resistance against Napoleon.

Before he left for Russia, however, he prepared an essay on war to leave with the sixteen year-old Prussian Crown Prince Friedrich Wilhelm (later King Friedrich Wilhelm IV, r.1840-1858), whose military tutor he had become in 1810. This essay was called "The most important principles of the art of war to complete my course of instruction for his Royal Highness the Crown Prince" (usually referred to as the "Principles of War").*14 This essay represented Clausewitz's theoretical development up to that point but was only a rather primitive precursor to his later magnum opus, On War. Its subject matter was largely tactical. While some of the more important theoretical concepts of On War were fairly well-developed ("friction," for example), many were embryonic and others entirely absent. In particular, and in great contrast to the later work, "Principles of War" is not notably sophisticated in historical terms. It is based almost entirely on the experience of Frederick the Great and the early wars with revolutionary France and Napoleon. Unfortunately, it has often been treated as a summary of Clausewitz's mature theory.

Portrait, Lieutenant-Colonel Clausewitz in Russian uniform c.1813In the Russian service, Clausewitz was somewhat hobbled by his ignorance of the Russian language. However, he spoke French (as well as English), as did many Russian aristocrats and the Russian imperial family, and there were many ethnic Germans in Russia and in the Russian forces. He participated in the drawn-out Russian retreat, fought in the slaughterhouse battle at Borodino, and witnessed the disastrous French retreat from Moscow, including the catastrophic crossing of the Beresina river. Boldly slipping through the French lines, he played a key role in negotiating the "Convention of Tauroggen," which brought about the defection of General H.D.L. Yorck von Wartenburg's Prussian corps from the French army. This risky venture infuriated the King but eventually forced Prussia into the anti-French coalition, leading directly to Napoleon's defeat and abdication in 1814 and to the resurrection of Prussia itself.

GneisenauNone of this won Clausewitz any immediate affection at court in Berlin, where he was referred to on at least one occasion as "Louse-witz,"*15 and his requests to rejoin the Prussian service were initially rebuffed. Still in Russian uniform, Clausewitz participated in many key events of the War of Liberation (1813-1814), but was frustrated by assignments that, while important, were not at the center of the most dramatic events. In something of a subterfuge, Scharnhorst arranged for him to serve as a Russian liaison officer to the Prussian army. In reality, he was an influential aide to General August von Gneisenau, who was Field Marshal G.L. von Blücher's chief of staff 1813-1815 and one of the principal leaders of Prussia's military rebirth. He often found himself in the thick of combat, as at Lützen/Grossgörschen in 1813, where he led several cavalry charges and was wounded. Scharnhorst died of wounds received in the same battle. Having done so much to challenge Prussia's subjugation by France, however, Clausewitz was viewed by many as a national hero. Thus Prussia's change of sides eventually led to his reinstatement in the Prussian army, as a full colonel, in April 1814.

During the campaign of 1815, Clausewitz served as chief of staff to Prussia's 3rd Corps, commanded by General J.A. von Thielmann. The corps fought at Ligny, successfully extricating itself from the Prussian defeat there. Then, outnumbered two to one, it played a crucial if sometimes uncelebrated rear-guard action at Wavre. This bloody action prevented Marshal Grouchy's detached forces from rejoining Napoleon at Waterloo.*16

In 1818, the King promoted Clausewitz to major-general and made him the administrative head of the General War College in Berlin. Despite the conservative reaction in Prussia after 1819, during which many of the liberal reforms of the war years were weakened or rescinded, he and Marie led a very active life among the highest social, intellectual, and political circles in Berlin. Having little to do with actual instruction at the school, Clausewitz spent his abundant leisure time writing studies of various campaigns and preparing the theoretical work which eventually became On War.

General Clausewitz returned to active duty with the army in 1830, when he was appointed commander of a group of artillery brigades stationed in eastern Prussia. When revolutions in Paris and Poland seemed to presage a new general European war, he was appointed chief of staff to Field Marshal Gneisenau and the Army of Observation sent to the Polish border.

Before leaving, he sealed his unfinished manuscripts. He never opened them again. Just what the book might have looked like had he completed it to his own satisfaction is an entertaining but usually fruitless subject of speculation for military scholars. In any case, it was evidently Clausewitz's intention never to publish it in his own lifetime. His reasoning was that this would free him from ego or career concerns that might affect his style and conclusions.

Although war was averted, Clausewitz remained in the east, organizing a sanitary cordon to try to stop the spread from Poland of the Cholera epidemic (the first case of the deadly disease reaching Europe, which caused a continent-wide panic). His friend Gneisenau soon died of that disease and Clausewitz took temporary command of the army. As a young one-star general, however, he was out-ranked by several of his subordinates and was therefore soon replaced by a more senior commander. He returned home to Breslau but shortly fell ill with cholera himself and died on 16 November 1831. He was fifty-one years old.

On War

With the aid of her brother and others, Clausewitz's wife Marie edited his unfinished manuscripts and published them as his collected works in ten volumes. The first three of these, comprising On War, appeared in 1832.*17 In subsequent editions, its ideas sometimes fell prey to the revisionist impulses of its various editors. The most scholarly reconstruction of the original work was undertaken by the German scholar Werner Hahlweg during the 1950s and 1960s. His editions provided the basis for the fourth English translation, that prepared by Michael Howard and Peter Paret and published in 1976.

The works most important in Clausewitz's reception in the English-speaking world are On War itself, its distant precursor Principles of War, and two campaign studies. The first of these campaign studies was The Campaign of 1812 in Russia, translated and published anonymously by a close friend of the Duke of Wellington in 1843. The second was The Campaign of 1815 in France. The latter work was not published in English until 2010 (when two versions appeared), but an abridged translation was prepared for Wellington. The Duke responded with a memorandum that was famous and influential in 19th-century Britain. This essay did a great deal to shape Clausewitz's modern reputation in Great Britain, even though the memorandum itself was systematically ignored after 1914 by British historians not eager to draw attention to the decisive Prussian role at Waterloo. These two studies of Napoleonic campaigns in which Clausewitz had himself participated represent different stages in the evolution of Clausewitz's ideas and reflect varying elements of his mature theories. The findings of the 1812 study were largely incorporated into On War. The 1815 study, however, Clausewitz's last, was never incorporated into the larger work, which hardly mentions the Waterloo campaign. Various other fragments of Clausewitz's work have been translated, but these have had little influence on his reputation in the English-speaking world. (Here are links to bibliographies of Clausewitz's writings in German and in English.)

On War has been translated into English several times (the principal translations are J.J. Graham's in 1873, Otto Mattijs Jolles's in 1943, and the Michael Howard/Peter Paret version in 1976). It is a hefty work and difficult reading, not because Clausewitz was a poor or disorganized writer but because the subject is a difficult one and his drafts unfinished. It has often been printed in three separate volumes; the newest single-volume English-language edition runs about 580 pages (not counting the accompanying commentaries). It is internally divided into eight books:

I. On the Nature of War

II. On the Theory of War

III. On Strategy in General

IV. The Engagement

V. Military Forces

VI. Defense

VII. The Attack

VIII. War Plans

To be understood, On War really has to be approached as a whole, but the intelligent reader needs to keep in mind that various sections reflect different stages in Clausewitz's intellectual and theoretical evolution. Books One, Two, and Eight are generally considered the most important and the most nearly "finished" (especially Book One), while older parts sometimes fail to connect with Clausewitz's most mature ideas. Some sections are often left out of abridged versions, especially Books Five, Six, and Seven, allegedly because they are tactical in nature and thus obsolete. This sometimes leads to serious misunderstandings of Clausewitz's arguments, for it is precisely in these books that he works out the practical implications of his ideas. For those who prefer to paint Clausewitz as the "apostle of the offensive," it is especially convenient to leave out Book Six, "Defense"—by far the largest, which demonstrated Clausewitz's controversial conviction that defense is inherently the stronger form of war.

One of the main sources of confusion about Clausewitz's approach lies in his dialectical method of presentation. For example, Clausewitz's famous line that "War is merely a continuation of Politik," while accurate as far as it goes, was not intended as a statement of fact. It is the antithesis in a dialectical argument whose thesis is the point—made earlier in the analysis—that "war is nothing but a duel [or wrestling match, a better translation of the German Zweikampf] on a larger scale." His synthesis lies in his "fascinating trinity" [wunderliche Dreifaltigkeit]. This synthesis resolves the deficiencies of the two earlier bald statements, indicating that war is neither "nothing but" an act of brute force nor "merely" a rational act of politics or policy. Rather, it is a dynamic, inherently unstable interaction of the forces of violent emotion, chance, and rational calculation on all sides.

Identifying precisely who was to benefit from reading On War, and precisely how, are perplexing questions. Clausewitz's practical purpose in writing included providing "military analysts" with a clear conceptual scheme for understanding war, in hopes of improving both its actual conduct and the literature discussing it. He hoped that such an understanding would improve the judgement of military commanders, but he also believed that "military genius" was more a matter of character, personality, and temperament than of intellect. Perhaps because of his awareness of his own character, he felt that intellectuals generally made poor commanders. Only a self-conscious intellectual, however, was likely to wrestle with a book like On War.

One of the deepest explorations of Clausewitz's intentions is provided by historian Jon Sumida in his Decoding Clausewitz: A New Approach to On War (Lawrence, KS: University Press of Kansas, 2008). Sumida's interpretation is discussed below under the heading "Clausewitz on History and Military History." His arguments on this important score are perceptive and convincing, though aspects of his treatment (and the very title of his book) annoyed some Clausewitz scholars and remain controversial.

Sumida asks whether it was Clausewitz's goal to provide a phenomenology of war—that is to say, a description of the essential nature of armed conflict—or to suggest some other route to understanding the problem. These are important distinctions; Sumida emphasizes the latter. But Clausewitz was an eclectic thinker who sought to integrate many diverse aspects of the problem, and it is difficult in practice to separate the two goals. On War certainly was not intended to provide a practical "cookbook" for commanders in the field. That approach is common in military doctrinal writing, and Clausewitz the practical soldier had himself written and taught doctrine during the Napoleonic Wars. But it was alien to Clausewitz's concept of military theory. "Given the nature of the subject, we must remind ourselves that it is simply not possible to construct a model for the art of war that can serve as a scaffolding on which the commander can rely for support at any time." Since theory could not be a guide to action, it must be a guide to study. It is meant to assist the student in his efforts at self-education and to help him develop his own judgement, "just as a wise teacher guides and stimulates a young man's intellectual development, but is careful not to lead him by the hand for the rest of his life." Clausewitz's studies of educational theory had convinced him of the limits of intellectualizing: Knowledge, he knew, was not ability, and abstract education must always be accompanied by practical experience. "[T]hese truths certainly need to be authenticated by experience. No theory, no general, should have anything to do with psychological and philosophical sophistries."*18 Indeed, one distinguishing characteristic of Clausewitz's approach to philosophy is his acceptance of practical realities. Actual experience always took precedence over the kind of abstract "truth" that can be transmitted by mere writing. Theory must never conflict with reality, and thus must be essentially descriptive of war, never prescriptive of action. There is of course a place for prescriptive doctrine, but that is useful only within a particular political/military context.

Clausewitz on History and Military History

To understand On War, to distinguish it from Clausewitz's earlier works, and to differentiate his ideas from those of other theorists, one must understand Clausewitz's evolving attitude towards history. Alone, his historical studies of Napoleonic campaigns would probably not have altered his approach to theory. As time went on, however, he also made detailed studies of earlier and quite different wars. These included seventeenth-century campaigns like those of Gustavus Adolphus and Turenne, the War of the Spanish Succession (1701-1714), and eastern European wars with the Turks. Thus On War reflects a much wider range of historical experience and a much more sophisticated approach to history as a discipline than did the earlier "Principles of War." Much of the misapprehension of his basic theories derives from the fact that he generally worked out their practical implications in a contemporary European context, but the underlying theory has universal implications. Clausewitz, along with broader historical philosophers like Hegel and Ranke, did much to shape our modern understanding of historical inquiry itself. He influenced Karl Marx (Marxism is a philosophy of history, not an economic theory) and especially military historian Hans Delbrück, generally considered the originator of modern "scientific" military history, who explicitly stated that to "fill out the lacuna that [Clausewitz] left" was one of his major purposes in writing. As Sumida notes, Clausewitz's ideas on "historical reenactment" prefigure the much later ideas of English-language historical theorist R. G. Collingwood.

For an excellent appreciation of Clausewitz as a historical innovator, see Sumida's recent works on Clausewitz. Sumida argues (and, with some caveats, I tend to concur with him) that On War is essentially "about learning how to do something—namely, how to exercise supreme command in war."

Clausewitz developed his approach to officer education in reaction to existing methods, which called for the study of historical narratives based on verifiable facts and for obedience either to rules or to guidance from less binding but still prescriptive principles. His rejection of these approaches was based on his conviction that effective command performance in war—and especially at the level of strategic decision—is the product of genius. Genius, defined as the command capability of the commander in chief, consists of a combination of rational intelligence and subrational intellectual and emotional faculties that make up intuition. Intuition, in particular, becomes the agent of decision in the face of difficult circumstances such as inadequate information, great complexity, high levels of contingency, and severe negative consequences in the event of failure. Clausewitz had observed that during the Napoleonic Wars, intuition had been improved by experience. He thus reached two conclusions. First, the primary objective of officer education should be the enhancement of intelligent intuition. And second, the only effective means of doing so during peace is to have officers replicate the experience of decision making by a commander in chief through historical reenactment of command decisions and reflect on that replicated experience. Replication, moreover, had to be based on actual events in the past because Clausewitz was convinced that resort to hypothetical case studies increased the possibility of setting up unrealistic governing conditions. Clausewitz recognized, however, that the historical record does not include many of the factors that affected the performance of commanders in chief of the past. That is to say, the domain of verifiable historical fact is critically incomplete, and thus an insufficient basis for productive historical reenactment. In order to remedy this deficiency, Clausewitz specified that verifiable historical fact had to be augmented by surmise about factors that are supposed to have been important. The basis of this surmise is a body of theory about those forces that affect decision making in war.*19

Clausewitz saw history in relative terms, rejecting absolute categories, standards, and values. The past has to be accepted on its own terms. The historian must attempt to enter into the mindsets and attitudes of any given period, the "spirit of the age." History is a dynamic process of change, driven by forces beyond the control and often beyond the comprehension or even detection of any individual or group. This attitude is particularly obvious in two key themes of On War that are missing in the Principles. These are the famous notion that "War is a continuation of politics with an admixture of other means" (i.e., organized violence) and the recognition that war can vary in its forms depending on the changing nature of policy and of the society within which it is waged.

Both insights derived from Clausewitz's relentless criticism of his own evolving ideas. Clausewitz's earlier ideas were based on the experience of the French Revolution and the wars against Napoleon, and they emphasized the quest for "decisiveness" in warfare. This approach could not, however, explain the relatively indecisive and limited warfare of earlier periods, unless earlier generations of soldiers were to be dismissed as fools—a solution Clausewitz ultimately rejected. He therefore determined that war could legitimately take on either the quasi-'absolute' form in which it had been waged by the revolutionary armies and Napoleon or assume a much more limited character, depending on its causes. Writing in the context of the politics of eighteenth-century Western Europe, he said that

most former wars were waged largely in [a] state of equilibrium, or at least expressed tensions that were so limited, so infrequent, and feeble, that the fighting that did occur during these periods was seldom followed by important results. Instead a battle might be fought to celebrate the birthday of a monarch (Hochkirch), to satisfy military honor (Kunersdorf), or to assuage a commander's vanity (Freiberg). In our opinion it is essential that a commander should recognize these circumstances and act in concert with their spirit.*20

Clausewitz saw the possibility that post-Napoleonic European wars would revert—or evolve—into forms more closely resembling those of the pre-revolutionary era. He called these weaker forms wars of limited objective and characterized them in various ways: "wars in which no decision is sought"; wars of limited aims; wars to seize a slice of enemy territory (either for its own sake or as a bargaining chip for use in attaining some other end).*21 Although the concept of limited war is clearly present and clearly important, it is by no means fully developed. That may be an advantage, of course. Leaving the concept open-ended makes it easy to adapt to changing circumstances.

On the other hand, Clausewitz also suspected that the Napoleonic wars would provide a model for future conflicts. Much of On War is therefore concerned with hard-fought struggles aimed at achieving a real political decision, and thus with military strategies aimed at actually disarming the enemy through the destruction (physical and/or moral) of his armed forces. This was not "limited" war, but neither was it "ideal" war in the theoretical sense described in his most evolved writings.

Clausewitz's rewriting of his draft manuscript for On War was largely a matter of reworking it to incorporate these insights. This process was never completed, cut short by his untimely death. It is therefore, in essence, two very different books superimposed. In some sections the earlier contempt for the limited form still shines through,*22 but the theoretical justification for waging such wars, while not fully explored, is undeniably present. The historian and political analyst in Clausewitz had triumphed over the purely empirical soldier.*23

Much of On War is devoted to discussions of the place of war in history, the practical uses of military history to the soldier, and the difficulties involved both in reading and in writing it. Clausewitz's most important technical contribution to the field of military history was his discussion of "critical analysis."*24 Clausewitz distinguished carefully between the functions of the historian and those of the military critic, even though he recognized that the two roles often went together. He maintained that historical research has nothing to do with either theory or criticism. It is the discovery, interpretation, and arrangement of "equivocal" facts (that is, facts that can then be interpreted in varying ways). Critical analysis is the tracing of effects back to their causes. "Criticism" proper is the investigation and evaluation of actions taken (or "means employed"), the consideration of alternative courses of action, the realm of praise and censure. In such evaluation, actions must be analyzed not only on their own level (i.e., tactical, operational,*25 strategic, political) but also as they interact at other levels. Theory provides the framework for analysis and judgement.

In using historical sources in this way, Clausewitz insisted that they not be abused. The sources available to the historian are, after all, inherently fragmentary. Often the most critical factors in any particular event are lost to us. There were four ways in which historical examples could be used in conjunction with theory:

1. To explain an idea, i.e., to give dimension to an abstract concept.

2. To show the application of an idea.

3. To demonstrate the mere possibility of some phenomenon.

4. To deduce a doctrine (this being by far the most difficult).

He was highly skeptical of any attempt to deduce any reliable doctrine from historical case studies and doubted that it could often be achieved. He therefore demanded the most exacting rules of evidence. Very little of the existing literature met these requirements, especially in the case of ancient history, where so much of the detail and context had been lost.

Given the difficulty of producing a truly useful historical study, the ease with which shallower efforts could mislead students, and the increasing loss of crucial context when dealing with older eras, Clausewitz advocated that military educators rely on the in-depth examination of one campaign (the more recent the better) rather than on broader but less exacting histories. Such an effort requires that the student do original research using primary sources rather than rely upon the pre-digested products of narrative historians. Such research forces the researcher to confront the vast gaps and contradictions in the sources, which published histories naturally smooth over. It is in wrestling with and realistically filling these gaps that much of the "historical reenactment" Sumida discusses takes place.

While it may contribute to a staff officer's technical virtuosity, however, the insistence on depth rather than breadth may constitute a weakness in Clausewitz's educational argument. Even if military educators fully recognized and tried to implement Clausewitz's educational ideas (which, lamentably, they do not), the kind of depth he advocated is difficult to achieve in practice and would require a focus and effort well beyond what American professional military educational institutions are likely to sustain. Thus any curriculum based on his argument is likely to fall well short of his goals—which is not to say it isn't worth trying.

In any case, no matter how deep a single study may go, unless it deals with the problem of contextual change it must inevitably leave the student less sensitive to the changeability of the "spirit of the age." Such a narrowly doctrinal approach tended to characterize the historical researches of the German General Staff, and German strategy typically suffered severely from such insensitivities. Hans Delbrück, on the other hand, avoided the narrow approach and emphasized the wider implications of Clausewitz's theories. His great work is the multivolume History of the Art of War within the Framework of Political History.*26 Delbrück is considered the founder of modern, professional, "scientific" military history, but his work was never popular with the German General Staff. While Clausewitz's original narrow argument may make sense for a small state like Prussia, whose likely enemies are well known and well understood, it is not applicable to a power like the United States, whose potential opponents offer infinite variety.

Three Competing Theorists

Before discussing further the actual content of Clausewitz's theories, it is useful to take note of three other important writers with whom his ideas are often contrasted. All of these writers differ from Clausewitz in noteworthy aspects, though none is truly his antithesis.

illustration, Sun Tzu    The ancient Chinese sage Sun Tzu lived, if he existed at all, sometime during the "Warring States" period of Chinese history (453-221 B.C.).*27 His book is generally considered the most important of the Chinese military classics and has had a significant if unmeasurable impact on the modern Japanese as well as on the military theories of Mao Zedong (who was also a close reader of Clausewitz), subsequent writers on revolutionary warfare, and the United States Marine Corps.

Sun Tzu is often offered up as the antithesis of Clausewitz, particularly on the issue of the "bloodless battle." His admonitions that a good general gains victory without battle and that no nation ever benefits from a long war are widely perceived as a direct contradiction to On War's emphasis on combat. In actuality, Sun Tzu and Clausewitz are much more complementary than antithetical, and there are many direct parallels.*28 Sun Tzu's understanding of history as a dynamic process and his subordination of military to political considerations certainly parallel Clausewitz's. Both stress destruction of the enemy's will rather than merely of his physical forces. Much of Sun Tzu's discussion of "bloodless struggle" refers to political and psychological matters rather than actual war, and he discusses actual combat at great length.*29 He tends to urge great reluctance to resort to warfare. Clausewitz similarly notes the dangers and uncertainties of war, but since his work is specifically on the conduct of military operations in war, rather than on policy itself, his emphases are different.

The two writers nonetheless often seem at odds. Like Mao, Clausewitz recognized that, while no one may benefit from a protracted war, neither will our side benefit from losing a short one. Thus Clausewitz was interested in exploring the possible value of dragging a struggle out. Clausewitzians, emphasizing the uncertainty, fog, and friction of war, generally believe that Sun Tzu badly exaggerated the control a commander can exert over the circumstances in which he operates. Clausewitz stressed the subordination of the military instrument to political control, while Sun Tzu's ideas on civil-military relations sound more like those of the soldier Helmuth von Moltke (discussed below). But if there is in fact any fundamental difference between the two writers (beyond Sun Tzu's extreme brevity, which most readers applaud for reasons not always entirely praiseworthy), it can probably be traced to their differing approaches to the balance-of-power mechanism. Sun Tzu's wars reflect a traditional Chinese ideal of uniting "all under heaven," despite the fact that the China of his era was split into warring states in many respects as unique as those of modern Europe. The Warring States period ended, in fact, in the unification of China, with the losing dynasties exterminated. Thus Sun Tzu's warfare tends, despite all his cleverness and subtlety, to be of the most brutal "winner-take-all, loser-fight-to-the-death" variety. Clausewitz thought the idea of unifying Europe's diverse peoples to be an absurdity, as one might expect in an opponent of Napoleon, and he recognized that even Napoleon's wars were often waged for limited military and/or political objectives.

Drawing of Jomini

Antoine-Henri Jomini, later Baron de Jomini, was a French-speaking Swiss (1779-1869).*30 Originally headed for a career in banking, young Jomini got carried away by the excitement of the French Revolution and joined the French army in 1798. He returned to business in Switzerland after the Peace of Amiens (1802) and began writing on military subjects. His Traité de grande tactique was first published in 1803. He continually revised, enlarged, and reissued it into the 1850s.*31

Rejoining the army in 1804, Jomini was accepted as a volunteer staff member by one of Napoleon's marshals.*32 He served in the Austerlitz and Prussian campaigns, then in Spain. He received an actual staff commission in the French army, allegedly at the behest of Napoleon, sometime after the battle of Austerlitz (1805). He served for a while as chief of staff to his long-time mentor, Marshal Michel Ney. Jomini's arrogance, irascibility, and naked ambition, however, often led to friction with his fellows and eventually to a falling-out with Ney. Nonetheless, Jomini was promoted to brigadier general and given a succession of fairly responsible staff positions, mostly away from actual troops. Following his recovery from the rigors of the Russian campaign, he was reassigned to Ney in 1813. However, he was shortly thereafter arrested under allegations of sloppy staff work. His ambitions thwarted by real or imagined plots against himself, Jomini joined the Russian army in late 1813. He spent much of the remainder of his long career in the Russian service.

During his actual military career, "Jomini ... [had been] a very minor figure, seldom mentioned in orders or dispatches, practically ignored in the memoirs of the officers who had served with him."*33 Most of what we hear of Jomini's supposed relationship with Napoleon comes from Jomini himself. Nonetheless, he became by far the best known military commentator of his day and maintained that position through zealous self-promotion. His most famous work, Summary of the Art of War, was written, like Clausewitz's Principles of War, for a royal prince to whom he was military tutor. Although long since retired, he advised Czar Nicholas during the Crimean War (1853-56) and Napoleon III during his Italian campaign (1859). Even during Jomini's lifetime, there were many prominent military men who viewed him with great skepticism. The Duke of Wellington considered him a pompous charlatan.*34 Napoleon himself is alleged to have said to his marshals, "You all think you understand war because you have read Jomini's book! Is it likely that I should have permitted its publication if it could accomplish that?"*35

In his maturity, Jomini grew wary of the revolutionary passions that had originally inspired him to take up the sword himself. Perhaps his dependence on the czar, one of the most conservative rulers in Europe, had some influence on his attitude. In any case, it is one of the ironies of history that Clausewitz, an officer of the conservative king of Prussia, should be the one to base his theories on the most radical legacies of the revolutionary period, while Napoleon's own staff officer and interpreter, Jomini, should aim his theories at the professional officer corps of essentially eighteenth century-style armies.

Jomini's military writings (especially his early works) are easy to unfairly caricature. They were characterized by a highly didactic and prescriptive approach, conveyed in an extensive, self-defined, geometric vocabulary of strategic lines, bases, and key points.*36 His fundamental prescription was simple: place superior power at the decisive point. In the theoretical work for which he was most famous, chapter XXXV of the Traité de grande tactique, he repeatedly emphasized the advantages of interior lines to the exclusion of other possibilities. Clausewitz's own sweeping critique of the poor state of military theory appears to have been aimed in large part at Jomini's early approach:

It is only analytically that these attempts at theory can be called advances in the realm of truth; synthetically, in the rules and regulations they offer, they are absolutely useless.

They aim at fixed values; but in war everything is uncertain, and calculations have to be made with variable quantities.

They direct the inquiry exclusively toward physical quantities, whereas all military action is intertwined with psychological forces and effects.

They consider only unilateral action, whereas war consists of a continuous interaction of opposites.... Anything that could not be reached by the meager wisdom of such one-sided points of view was held to be beyond scientific control: it lay in the realm of genius, which rises above all rules.

Pity the soldier who is supposed to crawl among these scraps of rules, not good enough for genius, which genius can ignore, or laugh at. No; what genius does is the best rule, and theory can do no better than show how and why this should be the case.*37

These passages immediately follow Clausewitz's sneers at the "lopsided character" of the theory of interior lines, comments unquestionably directed at Jomini.

Jomini was no fool, however. His intelligence, facile pen, and wide experience in the Napoleonic Wars made his writings a great deal more credible and useful than so brief a description can imply. Once he left Napoleon's service, he maintained himself and his reputation primarily through prose. His writing style—unlike Clausewitz's—reflected his constant search for an audience. He dealt at length with a number of practical subjects (logistics, seapower) that Clausewitz had largely ignored. Elements of his discussion (his remarks on Great Britain and seapower, for instance, and his sycophantic treatment of Austria's Archduke Charles) are clearly aimed at protecting his political position or expanding his readership. And, one might add, at minimizing Clausewitz's. He evidently perceived the Prussian writer—whose death thirty-eight years prior to his own was a piece of rare good fortune—as his chief competitor.

The fundamental differences between Clausewitz and Jomini are rooted in their differing concepts of the historical process and of the nature and role of military theory. Essentially, Jomini saw war as a stage for heroes, a "great drama." He saw the revolutionary warfare in which he himself had participated as merely the technical near-perfection of a fundamentally unchanging phenomenon. This static art could be modified only by superficial matters like the list of actors, technology, and transient political motivations. He drew his theoretical and practical prescriptions from his experiences in the Napoleonic wars. The purpose of his theory was to teach practical lessons: His target audience is not in doubt, his books being explicitly "designed for officers of a superior grade." Accordingly, Jomini's aim was utilitarian and his tone instructional. His writing thus appealed more readily to military educators and his key work, Summary of the Art of War (Précis de l'Art de la Guerre, 1838), became, in various translations, popularizations, and commentaries, the premier military-educational text of the mid-nineteenth century.*38

Much of the oft-noted contrast between Jomini and Clausewitz*39 can be traced to such philosophical factors and to the frequent abridgement of On War, which makes it appear much more abstract than Jomini's work when in fact they often discussed the same practical subject matter. Despite his insistence that theory must be descriptive rather than prescriptive in nature, Clausewitz frequently lapsed into instructive discussions of common military problems like contested river crossings, the defense of mountainous areas, etc.

It is also important to remember—but frequently forgotten—that the Summary was written after Jomini had read On War. Clausewitz's comments therefore do not reflect the modifications Jomini made afterwards to his original argument, for the Summary contains many adjustments clearly attributable to Clausewitz's influence. Jomini's essay on the state of military theory comments on the importance of morale; the impossibility of fixed rules (save perhaps in tactics); the need to assign limits to the role of theory; skepticism of mathematical calculations (and a denial that Jomini's own work—despite all the geometrical terminology and diagrams—was based on mathematics); the disclaimer of any belief that war is "a positive science"; and the clear differentiation between mere military knowledge and actual battlefield skill.*40

Jomini's recognition of the validity of many of Clausewitz's points did not lead him to adopt the Prussian philosopher's methods, for at least three reasons. First, he correctly distinguished his own work from Clausewitz's by pointing to its explicitly instructional purposes. Despite his agreement that war was essentially a political act, he pointed to the practical implications of this different focus: "History at once political and military offers more attractions, but is also much more difficult to treat and does not accord easily with the didactic species...."

Second, and in common with a number of Clausewitz's later detractors, he found the Prussian's approach intellectually arrogant, overly metaphysical, and simply too difficult to digest. Jomini stressed simplicity and clarity over a "pretentious" search for deeper truths. Further, he objected to what he saw as Clausewitz's extreme skepticism ("incrédulité") of all military theory save that in On War. For Clausewitz to reject Jomini's approach to theory while defending his own seemed somehow hypocritical.

Third, there was a personal element in Jomini's critique of Clausewitz. Clearly, he did on some level greatly admire Clausewitz's work. He regretted that the Prussian had not been able to read his own Summary, "persuaded that he would have rendered to it some justice." He was thus deeply wounded by the criticisms in On War. He expressed his bitterness in a number of sneers ("The works of Clausewitz have been incontestably useful, although it is often less by the ideas of the author, than by the contrary ideas to which he gives birth") and in accusations of plagiarism ("There is not one of my reflections [on the campaign of 1799] which he has not repeated"). These insults, because they refer to the Prussian by name, have more meaning to readers unfamiliar with On War than do the Summary's many concessions on theoretical issues. Thus it is often assumed that Jomini and Clausewitz are opposites. In fact, had the two men ever served together on the same staff, their practical advice on any particular issue might not have differed very much.

Helmuth von Moltke (the elder)

Quite unlike Jomini, the great German soldier Helmuth von Moltke ("the Elder," 1800-1891) was a self-professed disciple of Clausewitz. Austere but remarkably tactful, Moltke was that rarity, an intellectual and a staff officer who made his mark as a great commander.*41 He was selected as Chief of the Prussian General Staff in 1857 and remained in the job until 1888. It is for his work in this position that he is chiefly remembered today. Before Moltke brought it to prominence by masterminding the great Prussian victory at Königgrätz (1866), so obscure was the position of Chief of the General Staff that one general, upon receiving his orders, is said to have asked, "Who is this Moltke?" Working (not always harmoniously) with Otto von Bismarck as chancellor and Albrecht von Roon as minister of war, Moltke did a great deal to create the German military model that came to dominate military organizations throughout the world. Moltke's military behavior and his explicit discussions of military theory reveal a mind thoroughly grounded in the concepts of On War, but much more concerned with practical organizational matters than with strategic abstractions. (Of course, Clausewitz the soldier could have been described in much the same terms.) He left an intellectual and organizational legacy, however, that seems to many to contradict that of his master.

On the issue of the political control of war, Moltke argued that "Strategy can direct its efforts only toward the highest goal that the available means make practically possible. It best supports policy in working solely to further political aims, but as far as possible in operating independent of policy. Policy dare not intrude itself in[to] operations."*42 In other words, the political leadership could dominate only at the beginning and end of a war. In the meantime, the role of the military leadership was to reduce the enemy to helpless acquiescence in the political goals of the victorious state. Military leaders must be allowed to do their jobs without political interference. Moltke evidently believed that his views on this matter were in complete accordance with Clausewitz, quoting one of the latter's letters: "The role and right of military science, as regards policy, is principally to take care that policy does not demand things contrary to the nature of warfare, nor, through ignorance of the operation of the instrument, commit errors in the utilization thereof."

Otto von BismarckDuring the Franco-Prussian War of 1870-71, a classic clash between the military and political spheres occurred. In late 1870, after the destruction of the French field armies at Sedan and Metz, Moltke's army moved on Paris. Bismarck, the Kaiser's chancellor and chief political officer, wanted Paris brought under attack as soon as possible. His concern was not tactical but strategic and political: he worried that a protracted war might lead to some outside intervention disastrous to Prussian policy. Moltke resisted Bismarck's demands, citing technical military reasons. There was doubtless some truth to these, but Moltke was also motivated to resist the chancellor by institutional concerns. He had perhaps a political motive as well: Like many Germans, Moltke wanted to see the power of France—the incorrigible aggressor—permanently smashed. He feared that Bismarck was aiming at a less-than-maximized victory of the sort he had imposed on Austria in 1866. (This even though Bismarck's generosity in that case had resulted in huge political benefits—notably Austria's acquiescence in Prussia's domination of Germany and its neutrality during the war with France.) The Kaiser eventually overruled Moltke and placed the control of war policy in Bismarck's hands, but the constitutional issue outlasted Bismarck's tenure in office.

Moltke's attitude concerning the relationship of the military commander to the political leadership actually reflected not so much a disagreement with Clausewitz over the primacy of the political leadership as a fundamental problem in the Prussian—and later the German Empire's—constitution. Under Napoleon, political and military responsibility had been collocated, and in parliamentary governments the dominance of the political leadership was largely uncontested. In Prussia, however, the relationship was unclear. Bismarck was not an elected political leader like the prime minister of England: He was a servant of the ruler. As Moltke wrote to the Kaiser, the political and military chiefs were merely two parallel, "mutually independent agencies under the command of your majesty," and thus there could be no fundamental conflict between them.*43 In truth, the evolution of the army on the one hand and the Prusso-German state apparatus on the other meant that they eventually came to represent distinct (and sometimes antagonistic) social classes rather than the German nation as a whole. Unfortunately, Moltke's argument is easily taken out of this specific context.

Clausewitz and the Categories of War

Clausewitz's name is associated with a confusing number of categories of war, e.g., ideal war, real war, limited war, "war to render our opponent militarily or politically helpless," absolute war, and total war. Of these six, the first four represent ideas from Clausewitz's mature theory. The fifth, absolute war, represents an earlier stage of Clausewitz's thinking (and is an ancestor of the abstraction of "ideal war") but is still retained, with varying shades of meaning, in older parts of the text. The last, "total war," while widely attributed to Clausewitz, does not appear in On War at all and is in fact completely antithetical to his approach.

In seeking out the fundamental nature of Clausewitz's own mature theories, perhaps the best place to start is with some of the most common misconceptions of his argument. Such misconceptions are usually the product of writers who either never read On War (or read only the opening paragraphs or perhaps a condensation) or who sought intentionally to distort its content. The book's specific arguments are very clearly stated and rarely difficult to comprehend. The first of these misconceptions is the notion that Clausewitz considered war to be a "science."*44 Another (and related) misconception is that he considered war to be entirely a rational tool of state policy. The first idea is drastically wrong, the second only one side of a very important coin.

To Clausewitz, war (as opposed to strategy or tactics) belonged neither to the realm of art nor to that of science. Those two terms often mark the parameters of theoretical debate on the subject, however, and Clausewitz's most ardent critics (Jomini, Liddell Hart, the early J.F.C. Fuller) tended to be those who treated war as a science. As Clausewitz argued, the object of science is knowledge and certainty, while the object of art is creative ability. Of course, all art involves some science (the mathematical sources of harmony, for example) and good science always involves creativity. Clausewitz saw tactics as more scientific in character and strategy as something of an art, but the conscious, rational exercise of "military strategy," a term much beloved by theorists and military historians, is a relatively rare occurrence in the real world. "It has become our general conviction," he said, "that ideas in war are generally so simple, and lie so near the surface, that the merit of their invention can seldom substantiate the talent of the commander who adopts them."*45 Most real events are driven by forces like chance, emotion, bureaucratic irrationalities, and intra-organizational politics, and a great many "strategic" decisions are made unconsciously, often long before the outbreak of hostilities. If pressed, Clausewitz would have placed war-making closer to the domain of the arts, but neither solution was really satisfactory.

Instead, war is a form of social intercourse. The Prussian writer occasionally likened it to commerce or litigation, but more usually to politics.*46 The distinction is crucial. In both art and science, the actor is working on inanimate matter (and, in art, the passive and yielding emotions of the audience), whereas in business, politics, and war the actor's will is directed at an animate object that not only reacts but takes independent actions of its own. War is thus permeated by "intelligent forces." War is also "an act of force to compel our enemy to do our will," but it is never unilateral. It is a wrestling match—a contest between independent wills, in which skill and creativity are no more important than personality, chance, emotion, and the various dynamics that characterize any human interaction, including raw strength and power. When Clausewitz wrote that war may have a grammar of its own, but not its own logic, he meant that the logic of war, like politics, is the logic of social intercourse, not that of art or science.

The first few pages of On War set up a dialectical model of "ideal war" war that many readers find confusing, but ultimately this excursion is quite necessary. Ideal war, the intellectual descendant of his earlier term "absolute war" (which still appears in older parts of the book) represents the exploration of Clausewitz's initial thesis that "war is nothing but a wrestling match on a larger scale." Ideal war is a philosophical abstraction, a "logical fantasy" that is impossible to achieve in reality. It is war in a "pure" form, violence at its most extreme, unrestrained by intelligent forces or by the frictional effects of time, space, and human nature. It occurs for no particular reason and takes place in one near-instantaneous maximum effort by both warring parties. It aims at the utter overthrow of the enemy through the destruction of his physical means to resist. After exploring this notion of war as an act of pure force, Clausewitz demonstrates the flaws in that not-uncommon notion. While it is true that war is an act of force to compel our enemies to do our will, it is clearly much more than that. Its violence alone cannot account for our actual experience of war.

Unfortunately, it is clear that most would-be readers of On War have been stopped dead in their tracks by this dialectical discussion of ideal war.*47 Most make it no further than half-way through the first chapter, giving up on what seems to be a terribly abstract philosophical treatment of the problem—or, in some cases, thinking they have divined from it the whole of Clausewitz's bloodthirsty intent. However, this discussion of war in the abstract takes up only a small section of the first chapter (about five out of fifteen pages) and is atypical of the overall work. In the rest of the book, Clausewitz deals with "real war," i.e., the gritty reality of war as we actually experience it. He explores why real war is so different from his own abstract model, from the faulty constructs of other intellectuals, and from the pontifications of pedantic ivory-tower theorists. Real war is constrained by the ever-present social and political context, by human nature, and by the restrictions imposed by time and space. These factors forbid that the ideal should ever actually occur. While some aspects of ideal war can be approximated in reality, others cannot.


Clausewitz's classification of the varieties of war is very often misunderstood, owing not least to the fact that he never expunged the earlier form of this notion, "absolute war," which is preserved in older sections of On War. Initially, he thought of all warfare as the expression of a single, coherent, underlying idea whose objectives were constant and whose varying appearance in practice simply reflected different levels of energy and competence. Thus there was a single spectrum of war, of which Napoleon's conduct represented the high end approaching an "absolute." But as he came to recognize an essential difference between uses of force governed by limited political and/or military objectives and those driven by the goal of rendering one's opponent militarily helpless, the structure of his theory changed fundamentally. "Absolute" war, which had seemed a practical if seldom-achieved objective, evolved into the abstract, unrealistic, "logical fantasy" of "ideal war." Simultaneously, the ideal's dialectical opposite—"real war"—bifurcated into two tendencies (or "attractors," the latter a term from modern Complexity science) created by these very different categories of military and political objectives.

It is necessary to nail this point home: The spectrum of war in Clausewitz's mature theory does not run smoothly from "absolute" to "limited." Rather, we have on the one hand ideal war, an abstraction that never happens. On the other we have "real" war, which is always constrained by practical factors and occurs along a spectrum from the mere threat of force to conflicts which are unlimited in the sense that at least one of the antagonists is unwilling to accept any outcome other than the complete military and then political overthrow of his adversary. The mature Clausewitz referred to this end of the real-war spectrum not as "absolute war" but as war to render one's opponent "politically helpless or militarily impotent, thus forcing him to sign whatever peace we please."48



The graphics above provide one way of representing Clausewitz's concept of the way in which differing political and military objectives drive the varying character of war in the real world. While it represents Clausewitz's thinking as laid out in Book One, Chapter Two of On War ("Purpose and Means in War"), it reflects examination of other treatments, e.g., Robert A. Pape's and (especially) Hans Delbrück's. These graphics and terms were originally developed for the US Marine Corps' high-level manual MCDP 1-1: Strategy (1997), but the presentation has evolved somewhat. This slide is part of a long instructor-training PowerPoint entitled "The Relationship Between Political Objectives and Military Objectives in War."

Sumida calls the high end of real warfare "real absolute war." While most readers will find that term immensely confusing, it is justifiable if we accept Sumida's assumption that On War is "sufficiently complete (and the standard English translation of that German text sufficiently accurate) to reveal Clausewitz's considered major concepts." That assumption is probably valid enough for Sumida's specific purposes emphasizing Clausewitz's ideas concerning history, education, and the power of the defensive form of war. My own view, however, is that anyone attempting to base his own strategic-analytical framework on Clausewitz's mature thinking needs to take into account the evolutionary character of the existing book. Thus we must reject the terminology of absolute war as reflecting a model discarded for good reasons.

While the primary purpose of introducing the concept of ideal war is to set up Clausewitz's dialectical argument, it has other purposes (or at least functions). First, the neat logic whereby he sets up his ideal model serves to demonstrate the dangers of using pure logic to approach this complex subject: no abstract model can encompass all of the many messy factors that drive (and must drive) the behavior of real-world actors. Second, it provides a fixed benchmark—one which cannot be made obsolete by evolving events, as Jomini's comparable benchmark of Napoleonic warfare was—against which to measure actual developments in warfare. Of all real-world possibilities, only unrestrained thermonuclear war, which Clausewitz naturally did not envision, could closely match the ideal concept. Such a war has, of course, never occurred—probably because it is equally unrealistic. That is, while it may have become technologically feasible, there seems to be no comprehensible political motive that would impel a state to begin one (and, presumably, only states have sufficient resources to pursue such a war to its mutually suicidal extremes). The Cold War's nuclear strategists were unable to provide a credible political scenario to explain the nuclear exchanges they envisioned, and the nuclear powers were always careful to avoid creating a situation that might make such mutual suicide seem preferable to continued coexistence.*49

It is also important to note that Clausewitz's concepts of ideal and absolute war are both quite distinct from the later concept of "total war." Total war was a prescription for the actual waging of war typified by the ideas of General Erich von Ludendorff. Ludendorff actually assumed control of the German war effort during World War One and explicitly dismissed Clausewitz's position. Total war in this sense involved the total subordination of politics to the war effort—an idea Clausewitz emphatically rejected—and the assumption that total victory or total defeat were the only options. Total war involved no suspension of the effects of time and space, as did Clausewitz's concept of the ideal.*50

The Character of War in the Real World

Having rejected his initial thesis that war is nothing but an act of untrammeled violence, Clausewitz turned dialectically to the apparently more reasonable notion that war is a purely rational instrument of state policy. Writing in German, Clausewitz used the word Politik, and his most famous phrase has been variously translated as "War is a continuation of 'policy'—or of 'politics'—by other means." For the purpose of argument, he assumed that state policy would be rational, that is, aimed at improving the situation of the society it represented. He was quite aware, however, that in reality policy may be driven by very different motives. He also believed, along with most people of his era, that war was a legitimate means for a state's advancement of its interests. Because his actual discussion of war as an instrument of policy is usually read in isolation (if at all), Clausewitz is frequently convicted of advocating the resort to war as a routine extension of unilateral state policy. In fact, of course, Clausewitz's famous line is not meant to be an argument in itself. Rather, it is the antithesis to his earlier argument. Like any such dialectical discussion, it exposes contradictions or inadequacies in the given concepts and tensions between them, which can only be resolved in some synthesis of the two. Clausewitz normally seeks to maintain the tensions—as they are maintained in the world in which we actually operate—rather than to resolve them philosophically.

It is nevertheless possible to derive much of Clausewitz's message from the discussion of war as an act of policy or politics. In fact, the choice of translation for Politik—"policy" or "politics"—indicates crucially differing emphases on the part of the translator, for the two concepts are quite different in English. "Policy" may be defined as rational action, undertaken unilaterally by a group which already has power, in order to maintain and extend that power. Politics, in contrast, is simply the process (comprising an inchoate mix of rational, irrational, and non-rational elements) by which power is distributed within a given society.*51 (These are my definitions—Clausewitz never defines Politik.) And war is an expression of—not a substitute for—politics. Thus, in calling war a "continuation" of politics, Clausewitz was advocating nothing. In accordance with his belief that theory must be descriptive rather than prescriptive, he was merely recognizing an existing reality. War is an expression of both policy and politics, but "politics" is the interplay of conflicting forces, not the execution of one-sided policy initiatives.*52

The actual word Clausewitz used in his famous formulation is Fortsetzung, literally a "setting forth." Translating this word as "continuation," while technically correct, evidently implies to many that politics changes its essential nature when it metamorphoses into war.*53 This impression is contrary to Clausewitz's argument. War remains politics in all its complexity, with the added element of violence. It is important to remember, however, that On War is not about politics—for all its great length, it is very narrowly focused on this added element, organized violence, i.e., the conduct of military operations within war. It still retains an important political element, however, because it must deal with the impact of political factors on military operations.

The irrational and non-rational forces that affect and often drive politics have the same impact on war. On the side of rationality, it is true that Clausewitz argued that a party resorting to war should do so with a clear idea as to what it means to accomplish and how it intends to proceed toward that goal. The connection of war to rational political goals meant that wars could not be made to follow some fixed pattern. Rather, the conduct of wars would have to vary in accordance with their political purposes and context. His definition of "strategy"—that it was "the use of combats for the purpose of the war"—has been criticized for overemphasizing the need for bloody battle, but its key point is "the [political] purpose of the war."

If war—or, to be more precise, military force, for 'war' is by definition multilateral—was to be a tool of [unilateral] policy, then military leaders must be subordinate to political leaders and strategy must be subordinate to policy. As the Moltke-Bismarck clash demonstrated, this poses practical organizational problems. Like many of Clausewitz's teachings, his solution was not a simple prescription but a dualism: The military instrument must be subordinated to the political leadership, but political leaders must be made to understand its nature and limitations. Politicians must not attempt to use the instrument of war to achieve purposes for which it is unsuited. It is the responsibility of military leaders to ensure that the political leadership understands the character and limitations of the military instrument.

There is thus a gray area between soldiers' subordination to political leaders and their professional responsibility to educate those leaders in military realities. Exactly whose responsibility it is to sort out that ambiguity is a constitutional matter of some importance. Clausewitz did little to clarify it. In his original manuscript, Clausewitz said "If war is to be fully consonant with political objectives, and policy suited to the means available for war,... the only sound expedient is to make the commander-in-chief a member of the cabinet, so that the cabinet can share in the major aspects of his activities." This was altered in the second German edition (1853) to say "so that he may take part in its councils and decisions on important occasions."*54 Whether the change resulted from well-intentioned editorial intervention (for the original edition is full of inconsistencies, obscurities, and obvious editorial errors) or more sinister motivations is unclear. This minor editorial subversion certainly was not the cause of later German strategic errors, as some have implied.*55 This constitutional question aside, it is clear that Clausewitz demanded the subordination of military to political considerations throughout a conflict. As he said in 1831, "He who maintains, as is so often the case, that politics should not interfere with the conduct of a war has not grasped the ABCs of grand strategy."*56

Policy considerations also can demand actions that may seem irrational, depending on one's values. Clausewitz's desire that Prussia turn on Napoleon before the 1812 campaign would have demanded virtual state suicide in the short run, but he felt that the state's honor—and thus any hope for its future resurgence—required it. Clausewitz saw both history and policy in the long run, and he pointed out that strategic decisions are seldom final; they can often be reversed in another round of struggle. This side of Clausewitz is uncomfortable for modern Anglo-American readers because it seems to reflect a romantic view of the state as something that transcends the collective interest of its citizens. It can provide a philosophical basis for apocalyptic policies like Hitler's and Japan's in World War Two. Most modern readings of Clausewitz, including my own, tend to skate over such aspects of On War. They are simply too alien to the spirit of our age to have much meaning.

So much for the rational control of war. On the other hand, Clausewitz lived during the transition from the 18th-century intellectual period called the Enlightenment (which stressed a rational approach to human problems) to the age of Romanticism (which was ushered in by the disasters of the French Revolution and stressed the irrational, emotional aspects of man's make-up—including nationalism). His world view reflected elements of each. Clausewitz understood very well that there is much more to war than cool, rational calculation. So, after laying out the argument that war is "merely a continuation of policy," he begins to work towards the synthesis of his overall argument. This synthesis will reconcile the rational calculation of policy with the domain of the non-rational and even the irrational: "It follows that war is dependent on the interplay of possibilities and probabilities, of good and bad luck, conditions in which strictly logical reasoning often plays no part at all and is always apt to be a most unsuitable and awkward intellectual tool."*57

One of the most important requirements of strategy in Clausewitz's view is that the leadership correctly "establish ... the kind of war on which they are embarking."*58 This is often understood to mean that leaders should rationally decide the kind of war that will be undertaken. In fact, the nature of any given war is beyond rational control: It is inherent in the situation and in the "spirit of the age." Good leaders, avoiding error and self-deception, can at best merely comprehend the real implications of a resort to violence and act accordingly.

Further, a war often takes on a dynamic beyond the intentions of those who launched it. The conduct of war always rests—in unpredictable proportions—on the variable energies, interests, abilities, and character of the populations, the fighting elements, and the leaderships involved. Political leaders may easily misjudge or lose control of passions on their own side. Further, their opponents have similar such uncertainties as well as wills and creativity of their own. Because the flow of military events is uniquely shaped by the specifics of every situation, from its politics and personalities to the terrain and even the weather, the course of war is never predictable.

In 1976, Russell Weigley—one of the most influential of modern American military historians—attacked Clausewitz for missing this very point. Weigley had clearly developed his own recognition that war tends to escape rational control, but denied Clausewitz any understanding of that fact, so central to the Prussian's argument. Quoting Gerhard Ritter, he wrote that "what Clausewitz failed to see or at least to acknowledge is that war, once set off, may very well develop a logic of its own because the war events themselves may react on and alter the guiding will,... that it may roll on like an avalanche, burying all the initial aims, all the aspirations of statesmen." In fact, the Prussian writer had noted very clearly that "the original political objects can greatly alter during the course of the war and may finally change entirely since they are influenced by events and their probable consequences."*59 Like so many of Clausewitz's critics, Weigley—via Ritter—was engaged in reinventing the wheel. It is clear that Clausewitz's war is, despite all that intellect and reason can do to modify it, a game of chance and skill outside the bounds of rational control.

Would Prussia in 1792 have dared to invade France with 70,000 men if she had had an inkling that the repercussions in case of failure would be strong enough to overthrow the old European balance of power? Would she, in 1806, have risked war with France with 100,000 men, if she had suspected that the first shot would set off a mine that was to blow her to the skies?*60

Thus Clausewitz was hardly one to urge that the resort to war be taken lightly or routinely, nor to claim that its result would necessarily further the unilateral policy goals of the party who launched it.

Another source of unpredictability was what Clausewitz called "friction," stemming from war's uncertainty, chance, suffering, confusion, exhaustion, and fear. Friction stems from the effects of time, space, and human nature. It is the fundamental and unavoidable force that makes war in reality differ from the abstract model of ideal war. Events take time to unfold, with all that that fact implies. Purely military or political courses of action are deflected by countless delays and distractions. Strategic intelligence and battlefield information are often misleading or flatly wrong, and even the wisest order is subject to loss, delay, misinterpretation, poor execution, or willful disobedience. Every individual human being is a friction-producing cog in the machine of war, producing a delicate machine of endless complexity and unreliability. "Everything in war is very simple, but the simplest thing is difficult.... Action in war is like movement in a resistant element. Just as the simplest and most natural of movements, walking, cannot easily be performed in water, so in war it is difficult for normal efforts to achieve even moderate results."*61 It is perhaps no accident that slang terms like SNAFU and FUBAR originated in a military context. Much of what Clausewitz called "military genius" revolved around willpower. An iron will and a powerful sense of purpose are indispensable in overcoming the forces of friction. To some extent, of course, the causes of this difficulty are inherent in any large organization. Clausewitz saw it as unique to war because European armies were the first truly large, modern organizations.

Much of what Clausewitz called friction was, however, peculiar to war. This is particularly true of something that may seem obvious but escapes many theorists and armchair war planners: War is dangerous, and danger (either physical or moral) has an impact on the behavior of the participants. Under the influence of physical danger, "the light of reason is refracted in a manner quite different from that which is normal in academic speculation.... the ordinary man can never achieve a state of perfect unconcern in which his mind can work with normal flexibility."*62 Physical courage, however, is much more common than moral courage. It is lack of the latter that explains the frequent failure of men who have been successful—even dashing and heroic—as junior officers, but who become indecisive under the weight of real responsibility.

Jomini, whose practical military experience approximated Clausewitz's, understood perfectly well the practical importance of such factors. To him, however, they were unpredictable and therefore extrinsic to theory, while to Clausewitz they were so much a part of the fabric of war that theory must consider them to be intrinsic.

Clausewitz's insistence on the unpredictability of war raises some important issues. His writings are sometimes cited in support of various attempts at mathematically modeling war.*63 However, while much of Clausewitz's logic sounds vaguely mathematical and many of his individual propositions could no doubt be expressed in numbers, Clausewitz pointedly refrained from doing so. In essence, his explanation for this restraint is very similar to that of modern Complexity theory and nonlinear analysis as it is applied in such varied fields as physics, biology, and economics.*64 In demonstrating why long-range weather prediction is bound to fail, for instance, nonlinear theorists cite the so-called "Butterfly Effect": "a butterfly stirring the air today in Peking can transform storm systems next month in New York." Tiny differences in input may quickly become overwhelming differences in output. (A more dignified term for this effect is "sensitive dependence on initial conditions.")*65 Complexity theorists have demonstrated how even a few variables imperfectly known can reduce a complex system to a chaotic state. In war, there is an inherently unknowable number of largely unquantifiable variables, all of which may interact with one another in an unpredictable way. The list of parameters for any "equation of war" is fundamentally indeterminable.

Most natural phenomena are nonlinear. Dividing them along linear/nonlinear lines is similar to dividing the animal world into elephants and "non-elephant animals." Like the nonlinear theorists, Clausewitz insisted on keeping in view the whole phenomenon under discussion rather than attempting to draw conclusions from those few unrepresentative sub-components which might lend themselves to linear mathematical analyses. He focused on real-world experience, on concrete phenomena, rather than on simplified and inherently unrealistic models. "Just as some plants bear fruit only if they don't shoot up too high, so in the practical arts the leaves and flowers of theory must be pruned and the plant kept close to its proper soil—experience."*66 Clausewitz's historicist belief that war can change its nature depending on the "spirit of the age" echoes the "phase transitions" of the nonlinear scientists. Their observations of "symmetry at different scales" parallels Clausewitz's similar "ends and means" analyses of tactics, strategy, and politics, the same phenomena expressed at different scales in terms of time and space. The Prussian theorist would agree that mathematics had a place in war, as did other kinds of arts and sciences, but using math as a basis for theory or prediction was a laughable absurdity.

The significance of butterfly-like individual inputs and unique variables is particularly clear in Clausewitz's discussion of friction, of the significance of individual actions by any of the individual participants—of whatever rank—in military and political events, and of the impact of factors like terrain, always unique.

[Military] events are proof that success is not due simply to general causes. Particular factors can often be decisive—details known only to those who were on the spot. There can also be moral factors which never come to light; while issues can be decided by chances and incidents so minute as to figure in histories simply as anecdotes.*67

This emphasis on the particular and the specific permeates Clausewitz's mature theories. Frustrated readers seeking in his writings an answer to some particular problem sometimes bemoan this facet of his argument as an evasive "Well, that depends...," but that is just the point. The greatest familiarity with the most correct theory does not permit the decision-maker to skip the details. For good measure, Clausewitz heightens the frustration by noting that the details are very often missing or wrong.

Having demonstrated that we cannot adequately account for the observed phenomena of war through any of the rather simple propositions he has made thus far, Clausewitz provided his synthesis of the problem in his famous—but often misconstrued—discussion of what he called the "fascinating trinity" [wunderliche Dreifaltigkeit] of war.*68

War is thus more than a mere chameleon, because it changes its nature to some extent in each concrete case. It is also, however, when it is regarded as a whole and in relation to the tendencies that dominate within it, a fascinating trinity—composed of:

1) primordial violence, hatred, and enmity, which are to be regarded as a blind natural force;

2) the play of chance and probability, within which the creative spirit is free to roam; and

3) its element of subordination, as an instrument of policy, which makes it subject to pure reason.*69

The first of these three aspects concerns more the people; the second, more the commander and his army; the third, more the government. The passions that are to blaze up in war must already be inherent in the people; the scope that the play of courage and talent will enjoy in the realm of probability and chance depends on the particular character of the commander and the army; but the political aims are the business of government alone.

These three tendencies are like three different codes of law, deep-rooted in their subject and yet variable in their relationship to one another. A theory that ignores any one of them or seeks to fix an arbitrary relationship among them would conflict with reality to such an extent that for this reason alone it would be totally useless.

The task, therefore, is to keep our theory [of war] floating among these three tendencies, as among three points of attraction. [See illustration below.]

What lines might best be followed to achieve this difficult task will be explored in the book on the theory of war.*70 In any case, the conception of war defined here will be the first ray of light into the fundamental structure of theory, which first sorts out the major components and allows us to distinguish them from one another.

Let us analyze this quotation in some detail.

In arguing that war is more than a chameleon (an animal that merely changes color to match its surroundings, but otherwise remains identical), Clausewitz is saying that war is a phenomenon that, depending on conditions, can actually take on radically different forms. The basic sources of changes in those conditions lie in the elements of his "trinity."

The Clausewitzian trinity is often misrepresented (most famously by Israeli historian Martin Van Creveld, though he seems to have picked up his distorted view from U.S. Army Colonel Harry Summers) as comprising "the people, the army, and the government." Look more closely and you will realize that it is really made up of three categories of forces: irrational forces (i.e., "primordial violence, hatred, and enmity"); non-rational forces (i.e., forces not the product of human thought or intent, such as "the play of chance and probability"); and reason or rational calculation (war's subordination to reason "as an instrument of policy"). Later, Clausewitz connects each of those forces "more" to one of three sets of human actors: the people, the army, and the government. We insist on translating Clausewitz's word mehr as the English "more" (vice Howard/Paret's "mainly") because it is clear that each of the three categories that constitutes the actual trinity affects all of these human actors to some perpetually varying degree.

Thus, when Clausewitz speaks of war as a "total phenomenon," he is not talking about war in the abstract (ideal or absolute war), nor about war "in theory." He is talking about real war, war as we actually experience it, and he is describing just why it is that war is so dynamic, so unpredictable, so kaleidoscopic in its appearance. The visual metaphor provided in this excerpt from On War is a nearly exact analogy: Clausewitz is saying that theory must be, as war is, "like an object suspended among three magnets." He is referring to the observed scientific fact that such a pendulum, once set swinging among three centers of attraction, behaves in a nonlinear manner: it never establishes a reliably repeating pattern. As it enters a phase of its arc in which it is more strongly affected by one force than the others, it gains a momentum which carries it on into zones where the other forces can begin to exert their powers more strongly. The actual path of the suspended object is never determined by one force alone but by the interaction between them, which is forever and unavoidably shifting. It is a classic demonstration of "deterministic chaos."

The essence of this trinity lies, therefore, not its components but in their dynamic interaction. Attempts to render the trinity graphically as a static triangle, pyramid, or even pair of pyramids miss this point entirely. [For a detailed treatment of the Trinity, to include visual metaphors thereof, click here.]

Click on the video above to watch the source of Clausewitz's powerful visual metaphor.

The trinity also provides us with clues as to what Clausewitz meant by Politik, for the only element of the trinity that makes it unique to war is that the emotions discussed are those that might incline people to violence, whereas politics in general will involve the full range of human feelings. The policy aspects are those largely connected with rationality, whereas politics encompasses the whole trinity. The trinity metaphor therefore serves to sum up Clausewitz's approach to war and is the central element connecting all of his many ideas. An approach to theory which denies, or minimizes, or seeks to fix the role of any of these forces or the interaction between them is by definition wrong. The soldier who expects the events of war to unfold in any other way is doomed to be surprised, disappointed, and frustrated as events forever spin off on unpredictable trajectories.

So what, then, was Clausewitz's strategic prescription? Various writers have argued that Clausewitz was the advocate of a particular style of war, held by some to be that of "total war" or "absolute war" (two terms that represent quite different concepts, the first of which Clausewitz never used and the second of which he seems to have been in the process of dropping), and by others to be that of "limited" war. In fact, the mature Clausewitz advocated neither. Rather, he called for policy makers to choose a form of war, consistent with their goals and with the situation, from somewhere along the wide continuum of "real war." Although the younger Clausewitz of the "Instruction for the Crown Prince" tended towards a firm prescription of decisive objectives, the mature Clausewitz of On War did not. Readers easily detect that Clausewitz had some emotional attachment to war in its more powerful form as a result of his own experience with it, but intellectually he was quite clear on the validity of either. The philosopher's students are shown how to analyze a military problem, but left quite on their own as to what to do about the ones they actually face.

Other writers have claimed that Clausewitz was an advocate of concentric attacks, in contrast to Jomini's advocacy of "interior lines." In fact, Clausewitz spent more time discussing concentric operations in part simply because Jomini had already done so good a job explaining the opposite approach. The choice of either would depend, as always, on the specific situation.

Clausewitz did provide some guidance in choosing military objectives. Perhaps most prominent was the idea of focusing one's military efforts against the enemy's "center of gravity" ("Schwerpunkt"), which has become an omnipresent (and mind-numbing) concept in American military doctrine. Clausewitz's intent for this term is problematic, however—indeed, it became something of a verbal tic. He most often used it in very general terms to mean something like "the main thing" or "the key point at issue." He used it in tactical discussions to denote the main line of attack (i.e., the "main effort"). When applied to operations or strategy, however, the term sometimes assumed a more narrow definition. Insofar as the center of gravity "belongs" to one side or the other, it is the most important source of that side's strength. Operationally, it usually appears as the key (not necessarily the largest or most capable) enemy field force. Strategically, it is most commonly the enemy's military forces as a whole or in part, but it can be his capital or something less concrete, like the common interest of an alliance, the personality of a rebel leader, or even public opinion.

We should remember, however, the context for Clausewitz's use of this metaphor: war as a wrestling match. This metaphor is fundamental to Clausewitz's outlook on strategy, but translation problems sometimes obscure his point, as in Clausewitz's famous characterization of war as a "duel." Used in all of the English translations, it is not a very good substitute for the original German "Zweikampf," literally "two-struggle." A duel with sword or (particularly) pistol is based more clearly on skill than on raw strength and lacks the dynamic character, the multiple points of contact, and the mutability of a wrestling match, Clausewitz's actual imagery.*71 The latter metaphor provides a much better graphic image into which to fit the famous term "center of gravity." The center of gravity may be "the hub of all power and movement," but it is created by the interaction between the wrestlers and changes as they alter their relationship.

The term center of gravity comes from Mechanics. Clausewitz was clearly trying to use a scientific metaphor to force the reader to focus on key considerations rather than frittering away his energy on peripheral concerns. Unfortunately, Clausewitz's statement that "a center of gravity is always found where the mass is concentrated most densely" is scientifically incorrect, and the metaphor—while useful and interesting—suffers accordingly. In any case, as usual with Clausewitz, the correct identification of any center of gravity would have to be consistent with the character of the situation and appropriate to the political purposes of military operations. To seek for an all-purpose strategic prescription in Clausewitz's discussion of the center of gravity will therefore lead to the usual frustration. The rigid prescription simply is not there. Destruction of the enemy army is not the fixed goal of "Clausewitzian strategy."

Superficial reading of On War has, however, clearly left many readers confused on this point. Clausewitz's definition of strategy emphasizes battle, and he states quite clearly, time after time, that "there is only one means in war: combat." This may seem a rather grim thing to say, but most of us would probably concede that political events lacking a violent component should not be characterized as 'war.' Another of the subtleties that one must be aware of here is that by "combat" Clausewitz means not only the actual bloody clash of armed men on the field of battle but also potential or merely possible clashes.*72 The distinction is crucial. Clausewitz likened actual bloodshed to the occasional cash transaction in a business normally operating on credit. He did not say that a bloodless war of maneuver (à la Sun Tzu or Maurice de Saxe) is impossible, merely that maneuver by itself is meaningless. It must be backed up with the credible threat of battlefield success. An effective maneuver may create a situation in which the enemy is convinced that, if it comes to battle, he will lose more than he is willing to risk—and will therefore concede defeat. The maneuvering party must be prepared, however, for the possibility that his bluff will be called. The battle of Blenheim, 1704, provides a good example. The Franco-Bavarian leaders thought that they had maneuvered Marlborough's army into a position from which it must, according to the fashions of the time, retreat. Instead, Marlborough attacked and inflicted one of the greatest setbacks the French army was to suffer before May 1940.*73

This argument against a one-sidedly maneuverist approach to strategy was part of a larger point. Clausewitz argued that any kind of moderation or limitation in war must be based on a realistic expectation that it will be reciprocated, and that such expectations are often unrealistic. He used an interesting metaphor to make this point: "He must always keep an eye on his opponent so that he does not, if the latter has taken up a sharp sword, approach him armed only with an ornamental rapier."*74 Dealing with ideal war in the abstract, he had pointed out that "To introduce the principle of moderation into the theory of war itself would always lead to logical absurdity." This argument has much to do with Clausewitz's bloodthirsty reputation. One of the accusations made against Clausewitz is that his sanctions against "moderation" in theory led directly to the later German practice of military "Schrecklichkeit" (frightfulness). In fact, Clausewitz did not mean that moderation was absurd in practice, because the social conditions within civilized states and the relationships between them often made moderation an element of policy. He failed to belabor this point, however, and the accusation that it served to justify later German atrocities—to say it "caused" them would be absurd—is one of the hardest of all the indictments against him to evade. The theoretical point is hard to deny, but the language in which it was expressed is harsh.

Kind-hearted people might of course think there was some ingenious way to disarm or defeat an enemy without too much bloodshed, and might imagine this is the true goal of the art of war. Pleasant as it sounds, it is a fallacy that must be exposed: war is such a dangerous business that the mistakes which come from kindness are the very worst. The maximum use of force is in no way incompatible with the simultaneous use of the intellect.

Clausewitz's position is easier to understand if we consider the military transition Europe was forced to undergo at the end of the eighteenth century. As had happened to a great extent in Europe under the ancien régime, a society might well ritualize war into a mere game, for reasons of social order, humanitarianism, or economy. To accept such a conventionalization of war was in Clausewitz's view to fall into a trap. "The fact that slaughter is a horrifying spectacle must make us take war more seriously, but not provide an excuse for gradually blunting our swords in the name of humanity. Sooner or later someone [i.e., some revolutionary or alien invader] will come along with a sharp sword and hack off our arms."*75 The conventionalization of war in pre-Revolutionary Europe had created the ideal situation for a Napoleon to exploit.

Unfortunately, Clausewitz's not-unreasonable conviction that the state must always be prepared for a life-and-death struggle fed very easily into the unreasoning paranoia that led Germany's leaders to launch World War One. That Clausewitz himself was touched by such an attitude is heavily suggested in other essays he wrote.*76

Clausewitz believed, however, that the popular forces unleashed by the French Revolution, the event that had triggered his fears, were too powerful to be put back into the bottle. French successes had created a precedent that others would undoubtedly try to repeat. Clausewitz was therefore interested in the role of popular passions and public opinion in both politics and war. As a professional officer in a professional army with a venerable and glorious tradition, he was also sensitive to the quite different military virtues represented by the armies of revolutionary France or America. All of these considerations fell generally under the heading of "moral factors," and Clausewitz's work is famous for its emphasis upon them: "One might say that the physical seem little more than the wooden hilt, while the moral factors are the precious metal, the real weapon, the finely-honed blade."*77 These moral factors applied at both the individual level (usually discussed under the rubric of "military genius"), the organizational, and the societal.

Curiously, despite the fact that Clausewitz's emphasis on moral factors has always been noted, many of his critics argued that he had reduced strategy to the simplistic act of bludgeoning the enemy to death with overwhelming numbers. This accusation should not be dismissed out of hand as some modern analysts have done.*78 Clausewitz's method of argument on this point illustrates the ease with which his ideas can be distorted by sloppy reading or hostile editing. In his discussion of the armies of modern Europe, Clausewitz did indeed stress numbers:

Here we find armies much more alike in equipment, organization, and practical skill of every kind. There only remains a difference in the military virtues of Armies, and in the talent of Generals which may fluctuate with time from side to side.... From this we may infer, that it is very difficult in the present state of Europe, for the most talented General to gain a victory over an enemy double his strength. Now if we see double numbers prove such a weight in the scale against the greatest Generals, we may be sure, that in ordinary cases, in small as well as great combats, an important superiority of numbers but which need not be over two to one, will be sufficient to ensure the victory, however disadvantageous other circumstances may be.... The first rule is therefore to enter the field with an army as strong as possible. This sounds very like a commonplace, but still it is really not so.

It is clear that Clausewitz regarded the raising of the largest possible armies as an important factor in national strategy (and the ability to raise troops was clearly, in large part, a function of popular support for state policy). The number of troops "is determined by the government.... with this determination the real action of the war commences, and it forms an essential part of the strategy of the war...." Tactically, Clausewitz stressed concentration of superior force at the decisive point, as do virtually all military writers. "In tactics, as in strategy, superiority of numbers is the most common element in victory." This is the military equivalent of the businessman's adage, "Buy low, sell high." It is good advice, of course, but the real issues are how do you do it and why is it so hard? The key point here, however, is that raw strength is not to be despised in exclusive favor of clever stratagems: "The maximum use of force is in no way incompatible with the simultaneous use of the intellect. If one side uses force without compunction, undeterred by the bloodshed it involves, while the other side refrains, the first will gain the upper hand."*79

His argument was not, however, that the victor would necessarily be the side with the most men, simply that there was no excuse for going into combat with less than the maximum available power.

If we strip the combat of all modifications which it may undergo according to its immediate purpose and the circumstances from which it proceeds, lastly if we set aside the valour of the troops [dem Wert der Truppen] ... there remains only the bare conception of the combat ... in which we distinguish nothing but the number of the combatants. This number will therefore determine victory. Now from the number of things above deducted to get to this point, it is shown that the superiority in numbers in a battle is only one of the factors employed to produce victory; that therefore so far from having with the superiority in number obtained all, or even only the principal thing, we have perhaps got very little by it, according as the other circumstances ... happen to vary.... There remains nothing, therefore, where an absolute superiority is not attainable, but to produce a relative one at the decisive point, by making skillful use of what we have.... To regard [numerical superiority] as a necessary condition of victory would be a complete misconception of our exposition."*80

A partial reading of Clausewitz's views on surprise can be just as misleading. His bald statements that it "would be a mistake ... to regard surprise as a key element of success in war" and that "surprise has lost its usefulness today" are confusing if taken out of context, and that often seems to be the case.*81 Also controversial is his argument that surprise often favors the defense. Overall, Clausewitz actually emphasized the concept of surprise strongly, suggesting that—defined as "the desire to surprise the enemy by our plans and dispositions, especially those concerning the distribution of forces"—it "lies at the root of all operations without exception, though in widely varying degrees depending on the nature and circumstances of the operation." He clearly appreciated its psychological impact and felt that almost the only advantage of the attacker rested in surprise.

* * *

As a man of his times, Clausewitz obviously believed in the practical utility or necessity of war, and he was very conscious of its offer of individual "glory." As a Prussian patriot he had little sympathy for the claims of subjugated peoples such as the Poles. He was, however, no advocate of a policy of conquest. Although he is often portrayed as the "high priest" of Napoleon, this view ignores the fact that he was a die-hard opponent of the French emperor. He was detached enough to admire Bonaparte as a professional soldier, but his experience of the Napoleonic wars convinced him of the power of nationalism and of the balance-of-power mechanism. In his view, those forces would generally lead to the destruction of any would-be Alexander or Napoleon, at least in the European context. Thus, the wars he describes are often those of Napoleon, but his strategic biases are essentially conservative and anti-revolutionary. The approach he takes is not Napoleon's but that of the Emperor's most capable enemy, Scharnhorst. To call Clausewitz the "codifier of Napoleonic warfare" as his critics (and some of his supporters) often have, is to miss this important point.*82

The clearest evidence of Clausewitz's faith in the balance-of-power mechanism lies in his analysis of the dynamic relationship between the offense and the defense.*83 He has been portrayed by various writers as a proponent of one form or the other, but as in so many important aspects of his theory, his actual approach was instead to set up a dualism: defense is the stronger form of war, but it has a negative object (self-preservation); offense is the weaker form, but it alone has a positive purpose (increasing one's strength through conquest). Any realistic military theory must embrace both.

The sources of the fundamentally greater strength of the defense are many. In a sense, the defensive form's superiority is self-evident: Why else does the weaker party so often resort to it? At the tactical level, Clausewitz was impressed by the power of entrenchments—and alarmed at the tendency of some fashionable and generally inexperienced theorists to dismiss them. He was also interested in fixed fortifications, although he warned against over-reliance upon them and made some careful observations upon their correct use. He was impressed as well by the defender's frequent ability to choose his own ground. In most battles, however, both sides use both offensive and defensive methods and losses tend to be fairly equal until one side or the other breaks. Therefore he strongly emphasized the pursuit, which permits the infliction of disproportionate losses on the loser. At the tactical level, however, technological and other factors may alter the balance between offense and defense, so his general argument about the inherently greater strength of the latter is not applicable there.

Much more important were the operational and strategic aspects of defense. However strongly an offensive may start out, it inevitably weakens as it advances from its original base. The need to provide garrisons, to maintain the lines of supply and communications, the greater physical strain on troops in the attack, all degrade the aggressor's force. Meanwhile, the defender falls back upon the sources of his strength. Every offensive, however victorious, has a "culminating point." If the defender has enough time and space in which to recover (and Russia offered an excellent example, which Clausewitz noted long before Napoleon's disaster there in 1812-13), the aggressor inevitably reaches a point at which he must himself take up the defense. If he pushes too far, the equilibrium will shift against him. The aggressor, in his own retreat (often through devastated territory), cannot draw on the defender's usual sources of strength—physical or psychological.

Moreover, public opinion and the balance-of-power system are more likely to favor the strategic defender, since significant conquests by one contender will threaten the rest. Eventually, the conqueror will reach a "culminating point of victory" at which his successes provoke sufficient counteraction to defeat him.

In aggressive wars in which the defending population is aroused, Clausewitz was extremely pessimistic about the prospects of the aggressor. That stance was motivated in part by Prussia's dilemma as an occupied power but well justified by the examples of Spain and Russia. His powerful and pervasive argument that defense is inherently the stronger form of war was never explored in any great depth (in the English language, at least) until Jon Sumida powerfully raised the problem in Decoding Clausewitz (2008). That argument turns in significant part on the passions of the people, which tend naturally to be more intense on the part of a population fighting on its own soil than they can ever be on the part of soldiers fighting far from home. This analysis has always been extremely controversial, for many reasons. For one thing, simply because the defense is inherently stronger does not mean the defender will win: There are other factors and other asymmetries to consider. Nonetheless, it has been amply borne out in recent times in Chechnya, Iraq, and Afghanistan.

The essence of the defense is waiting: waiting until the attacker clarifies his own intentions; waiting until the balance of forces shifts; waiting for any improvement in the defender's situation, whether from the culminating process described above, from outside intervention, from mobilization of his own resources, or from some chance development. Time is almost always on the side of the defender.

Waiting, however, does not imply mere passivity, and a passive defense is not at all what Clausewitz was describing. His vision of any effective defense was profoundly active. If the defense functions essentially as a shield, it is best "a shield made up of well-directed blows."*84 Defense must shift at some point to the offense, the "flashing sword of vengeance." Thus it is easy to find in On War isolated quotations which seem to glorify the offensive. It is nonetheless the interaction of the two forms that concerned Clausewitz.

The dynamic relationship between defense and offense is just one of a larger group of concepts which might collectively be labeled the "dynamics of war." These would include the emphases on friction and morale, the diminishing force of the offensive, the "culminating point of victory"; in short, all of the factors that prevent war from being a linear process, that create the unpredictable see-sawing between opposing wills and powers that characterizes our real-world experience of war.


It was Clausewitz's great goal to bridge the gap between theory and practice. Unfortunately, his work has often fallen into the crack it sought to span, perceived as being too concrete and pragmatic for the intellectual, too complex and ambiguous for the active politician, and too ethereal for the practical soldier. Too many people on all sides of the chasm have simply failed to engage the profound ideas in On War.*85 More fundamentally, the gap represents a real dichotomy between the values and perceptions of scholars and soldiers, with their sometimes well-founded suspicions of one another. Perhaps inevitably, perhaps as the result of correctable failings in their education, practical soldiers tend to lack the deep historical understanding that is so helpful in internalizing Clausewitz's historicist argument, understanding his dialectical approach, and distinguishing the practical utility of his concepts.

There are, however, a great many other factors which tend to block our appreciation of Clausewitz. These range from national prejudice and personal ego to fundamental problems of human perception. The reader's personal experience has a great deal to do with how he or she comprehends On War: To say that readers accept—or even perceive—only what they are able to recognize as restatements of their own views or experiences is almost certainly going too far. But not by much. The book is often less a window into reality than a mirror for its reader, perhaps necessarily so. This has been my own experience with it. When I first read it as an undergraduate at the College of William and Mary in 1974, it was the abstract discussion of "ideal war" and the notion of war as an instrument of rational policy that seemed to me to be its essence. When I read it during my time as a soldier, it was the discussion of friction, chance, and moral factors that most struck me. When I was later working purely as a historian, it was Clausewitz's historicist philosophy that provided the key to understanding. As a military educator and doctrine writer, I came to focus on those operational concepts that have worked their way into U.S. doctrine, like the "center of gravity" and the "culminating point." Every time I have read On War, it has seemed a different book, but it is only myself who has changed.

Thus it is little wonder if survivors of the trench warfare of 1914-1918 saw their experiences in On War's pages, just as Vietnam veterans tend to see in it a textbook on what went wrong in their war. That this should be the case would not have surprised Clausewitz, who insisted that personal experience (or a lack of it) was essential to any understanding of the phenomena of war.

These lessons certainly do not justify the complaint of many academics and soldiers that Clausewitz's theories are valueless because they are so endlessly flexible.*86 Clausewitzian theory is like any fine tool available to artists, scientists, or soldiers. The qualities of its product depend on the peculiarities of the mind that wields it. However the predispositions of the reader may affect his view of war, the lens offered by Clausewitz provides for a much more distinct vision.

And that lens is very important, not only for its own sake but because of the role Clausewitz's theories—and misunderstandings thereof—have come to play in the American national security community. On War gave shape to the most important formulations of the final "lessons learned" from the Vietnam experience, as expressed in Harry Summers's work and in the Weinberger Doctrine. The impressive "jointness" with which the American armed forces and connected agencies waged the Persian Gulf War in 1990-1991 and since is traceable to a very significant, if unquantifiable, extent to the common political/military conceptual base that this study engendered. Clausewitz has provided the intellectual common ground that formal doctrine has always sought but—because of its unavoidably narrow focus, usually single-service orientation, and prescriptive intent—failed to provide. The value of that common ground lies in the very flexibility of Clausewitzian theory that many have found so frustrating: It provides a common set of concepts and intellectual tools, greatly facilitating analysis and discussion while leaving the conclusions to be reached as open as ever to creativity and to differing goals and points of view. But invocation of the aura of Clausewitz's name also contributed to an increasingly dysfunctional American strategic culture that—in the view of the present author, at least—came increasingly in the era after 11 September 2001 to embrace war as merely another way to continue bad policy by other means. Writing in 2015, it is obvious that another major revival in Clausewitz Studies is underway, which—as has happened many times before—is a reaction to the failures of modern military and political pundits to offer a useful replacement for Clausewitz's approach.

The dominance that Clausewitz has exercised in American military-intellectual circles over the last forty-plus years has bored or outraged many thinkers unable or unwilling to probe its complexities. It has provoked a reaction on the part of would-be competitors like Martin van Creveld and John Keegan, ahistorical ideologues like Mary Kaldor and the "New Wars" scholars, and soldiers embittered by an unproductive form of warfare that they've been told is "Clausewitzian."*87 Nonetheless, if Clausewitz's works at some point become relegated to the same dusty bookshelves as those of most of his contemporaries, it will probably be because, at long last, his key insights have been thoroughly absorbed and his own expression of them superseded.*88 If not, we can look forward to another Clausewitzian revival after the next military disaster.

The Trinity: visual metaphor Yin Yang Yong


1. This is a much-revised version of Chapter 2, "Clausewitz and His Works," of Christopher Bassford, Clausewitz in English: The Reception of Clausewitz in Britain and America, 1815-1945 (New York: Oxford University Press, 1994), pp.9-33. It has been much modified and re-designed to serve as a stand-alone introduction to the field of Clausewitz studies. It was written at the U.S. Army war College in 1996 and has been continuously updated since.

2. Especially the "capstone" series: MCDP 1: Warfighting; MCDP 1-1, Strategy; MCDP 1-2, Campaigning; and MCDP 1-3, Tactics (all 1997). FMFM 1 (1989) and its successor, MCDP 1, both drafted by John Schmitt, also have a substantial flavoring from Sun Tzu, whose ideas (or attitudes) permeate USMC thinking. I wrote MCDPs 1-1 and 1-2 myself, clearly coming in with a Clausewitzian bias. Nonetheless, Schmitt and I pretty much saw eye-to-eye on every significant issue.

3. Command and General Staff School, Principles of Strategy for an Independent Corps or Army in a Theater of Operations (Fort Leavenworth, KS: U.S. Army Command and General Staff School Press, 1936), p.19.

4. Carl von Clausewitz, eds./trans. Michael Howard and Peter Paret, On War (Princeton: Princeton University Press, 1976/1984), Book One, Chapter 1, section 25.

5. On War, Book Eight, Chapter 6.

5.1. See Vanya Eftimova Bellinger's excellent biography of Clausewitz's wife: Marie von Clausewitz: The Woman Behind the Making of On War (Oxford University Press, 2016), p.222.

6. General Jakob Meckel, quoted in Stewart L. Murray, The Reality of War: An Introduction to Clausewitz (London: Hugh Rees, 1909), p.7.

7. On War itself is often misleading for much the same reason: Clausewitz placed great stress on some points simply because they were antagonistic to the fashions of his own time, leaving later readers somewhat confused about those points' importance to his overall scheme. The issue of moderation in war, or his comments on the idea of the "bloodless victory," are examples. Clausewitz's seemingly contradictory comments on the value of intelligence and surprise probably owe something to this factor also.

8. The latter position, however, was not then nearly so important as it became later, under the stewardship of Helmuth von Moltke.

9. On Scharnhorst's ideas and influence, see Charles Edward White, [Graduate, USMA, at last report Command Historian, U.S. Army Infantry School, Fort Benning], The Enlightened Soldier: Scharnhorst and the Military Gesellschaft in Berlin, 1801-1805 (New York: Praeger, 1989).

10. Carl von Clausewitz, Historical and Political Writings, eds./trans. Peter Paret and Daniel Moran (Princeton: Princeton University Press, 1992), p.231.

11. Ibid. Moran's treatment of Clausewitz's politics is excellent. See also C.B.A. Behrens, "Which Side was Clausewitz on?" New York Review of Books, October 14, 1976, pp.41-44.

12. Clausewitz, Nachrichten über Preussen in seiner grossen Katastroph (Berlin: E.S. Mittler, 1888). Partial English translations of this study can be found in Paret and Moran, Historical and Political Writings, and Carl von Clausewitz, "Notes on the Jena Campaign," Ed./trans, Colonel Conrad H. Lanza, FA/USA, in Jena Campaign Sourcebook (Fort Leavenworth: The General Service Schools Press, 1922).

13. In 1812, Clausewitz made a rather passionate statement of his principles and motives for resigning, called "Bekenntnisdenkschrift," in Carl von Clausewitz, Politische Schriften und Briefe, ed. by Hans Rothfels (Munich: Drei Masken, 1922), pp.80-118. Part of this is available in English in Karl von Clausewitz, ed./trans. Edward M. Collins [Colonel, USAF], War, Politics, and Power: Selections from On War, and I Believe and Profess (Chicago: Henry Regnery Company, 1962). 

14. Die wichtigsten Grundsätze des Kriegführens zur Ergänzung meines Unterrichts bei Sr. Königlichen Hoheit dem Kronprinzen, often published as an appendix to On War. It is available in two English translations: J.J. Graham's (1873) and Hans Gatzke's (1942). It is generally referred to as Principles of War or "Instruction for the Crown Prince."

15. Re "Lausewitz," see Peter Paret, Clausewitz and the State: The Man, His Theories, and His Times (Princeton: Princeton University Press, 1976), pp.232. This is the best English-language biography of Clausewitz, but it is rather narrowly focused on Clausewitz the intellectual. For a truly rich look at Clausewitz in the social and political context of Prussia, see Vanya Eftimova Bellinger's biography of Clausewitz's wife: Marie von Clausewitz: The Woman Behind the Making of On War (Oxford University Press, 2016). See also Donald Stoker's biography, Clausewitz: His Life and Work (Oxford University Press, 2014), which focuses on Clausewitz's military career.

16. Clausewitz's experience at Wavre is analyzed in Paret, Clausewitz and the State, 247-250; Parkinson, Clausewitz: A Biography, chapters 13 and 14; Raymond Aron, trans. Christine Booker and Norman Stone, Clausewitz: Philosopher of War (Englewood Cliffs, N.J.: Prentice-Hall, 1985), pp.30-31.

17. The remaining seven volumes of Clausewitz's collected work, mostly campaign studies, appeared over the next few years. Other bits and pieces of his writing were published over the remainder of the century, and a considerable literature grew up in Germany around his life and views. See's German bibliography.

18. On War, Book Two, Chapter 2, section 15.

19. From Jon T. Sumida, "The Clausewitz Problem," Army History, Fall 2009, pp.17-21. This short piece well encapsulates Sumida's controversial—but insightful, useful, and predominantly right—arguments in his book Decoding Clausewitz: A New Approach to On War (Lawrence, KS: University Press of Kansas, 2008).

20. Book Three, Chapter 18, On War.

21. See especially Book Eight, Chapter 5, "Closer Definition of the Military Objective—Continued: Limited Aims."

22. E.g., On War, Book Three, Chapter 16.

23. This view of Clausewitz's use of history is not universally held. See, for example, John Gooch, "Clio and Mars: The Use and Abuse of History," Journal of Strategic Studies, v.3, no.3 (1980), pp.21-36. Gooch argued (although his points were somewhat inconsistent) that Clausewitz had used history to support his theories, rather than deriving his theories from history. In fact, he did neither: he derived his theories from experience (both his own and historical) and tested them against history. What makes Clausewitz remarkable as a military theorist is that he actually allowed the test results to modify his argument, sometimes in a radical manner. Gooch's view seems to be based on a rather purist idea of the historian's mission. This aspect of On War will no doubt remain a source of controversy, involving as it does fundamental disputes over the nature of history as a discipline and the values of professional historians.

24. See particularly Book Two, Chapters 5 ("Critical Analysis") and 6 ("On Historical Examples"), and Book Eight, Chapter 3.B. ("Scale of the Military Objective and of the Effort to be Made").

25. The "operational level" is a modern construction encompassing much of what Clausewitz discussed as "strategic"—the use of an engagement for the purpose of the war. Clausewitz's narrow definition of the word strategy is sometimes taken as proof of his primitiveness, but the modern inflation of the word to encompass just about everything has also provoked a reaction. See Hew Strachan, "The Lost Meaning of Strategy," Survival, Autumn, 2005.

26. Hans Delbrück, trans. [Brigadier General, USA] Walter J. Renfroe, Jr., History of the Art of War within the Framework of Political History, 4 vols. (Westport, CT: Greenwood Press, 1975-85).

27. Sun Tzu has been translated into English many times. Sun Tzu, trans. Samuel B. Griffith [Brigadier General, USMC], The Art of War (Oxford: Oxford University Press, 1963) provides much of the basis for the present discussion.

28. A detailed comparison of Clausewitz and Sun Tzu is outside the boundaries of this study. See, however, Michael I. Handel, Sun Tzu and Clausewitz: The Art of War and On War Compared (Carlisle Barracks, PA: Strategic Studies Institute, U.S. Army War College, 1991), which generally accords with my argument.

29. Winning an interstate struggle without combat might be desirable from Clausewitz's point of view, but that would in his view be purely a matter of politics. While war is a continuation of politics, by Clausewitz's definition it requires the admixture of violence. Much of Clausewitz's emphatic rejection of the "bloodless victory" idea was prompted by the fanciful musings of earlier theorists of a warfare based exclusively on bloodless maneuver. There may be a direct connection of sorts here, for Sun Tzu's work was (badly) translated into French in 1772 [Jean Joseph Marie Amiot, Art militaire des Chinois (Paris: Didot l'ainé)] and was popular with writers of the late Enlightenment. The idea also appears, however, in earlier European works like those of Maurice de Saxe (1696-1750), who has likewise been contrasted to Clausewitz.

30. On Jomini, see Crane Brinton, Gordon A. Craig, and Felix Gilbert, "Jomini," in Edward Mead Earle, ed., Makers of Modern Strategy: Military Thought from Machiavelli to Hitler (Princeton: Princeton University Press, 1944); Michael Howard, "Jomini and the Classical Tradition," in Michael Howard, ed., The Theory and Practice of War (New York: Praeger, 1966); John Shy, "Jomini," in Peter Paret, ed., Makers of Modern Strategy: From Machiavelli to the Nuclear Age (Princeton: Princeton University Press, 1986).

31. Henri Jomini, Traité de grande tactique (Paris: Giguet et Michaud, 1805).

32. The best English-language discussion of Jomini's military career can be found in John R. Elting, "Jomini: Disciple of Napoleon?" Military Affairs, Spring 1964, pp.17-26. Unlike most biographical discussions of the Swiss, which are based on his own highly colored reminiscences to people he wished to impress, Elting's study is based on Xavier de Courville, Jomini, ou de le Devin de Napoleon (Paris: Plon, 1935): "Written by Jomini's descendants, from his personal papers, it is the most impartial of his biographies."

33. Elting, "Jomini." 

34. [Francis Egerton, Lord Ellesmere], "Marmont, Siborne, and Alison," Quarterly Review, v.LXXVI (June and September 1845), pp.204-247, a joint venture of John Gurwood, Egerton, and Wellington himself. See Archives of the John Murray Company, manuscript index to v.LXXVI, Quarterly Review; J.H. Stocqueler (pseud.), The Life of Field Marshal the Duke of Wellington (London: Ingram, Cooke, and Company, 1853), v.II, pp.330.

35. Quoted in Robert M. Johnston, Clausewitz to Date (Cambridge, Mass.: The Military Historian and Economist, 1917), 9-11.

36. See, for example, Articles XVIII-XXII of the Summary

37. On War, Book Two, Chapter 2. Clausewitz's sarcastic concluding line has confused many writers. See Cliff Rogers, "Clausewitz, Genius, and the Rules" and Jon Sumida's reply in The Journal of Military History, October 2002.

38. For Jomini's theoretical writings in English translation, see Antoine-Henri Jomini, trans. Col. S.B. Holabird, U.S.A., Treatise on Grand Military Operations: or A Critical and Military History of the Wars of Frederick the Great as Contrasted with the Modern System, 2 vols. (New York: D. van Nostrand, 1865); Baron de Jomini, trans. Major O.F. Winship and Lieut. E.E. McLean, The Art of War (New York: G.P. Putnam, 1854). Important derivative works include Dennis Hart Mahan's instructional works for West Point; Henry Wager Halleck, Elements of Military Art and Science (New York: D. Appleton and Company, 1846); Edward Bruce Hamley (1824-93), The Operations of War Explained and Illustrated (London: William Blackwood and Sons, 1866).

39. Most discussions of Jomini compare him to Clausewitz. For explicit efforts to do so, see Department of Military Art and Engineering, USMA, Clausewitz, Jomini, Schlieffen (West Point, 1951 [rewritten, in part, by Colonel [USA] John R. Elting, 1964]); J.E. Edmonds, "Jomini and Clausewitz" [a treatment extremely hostile to the German], Canadian Army Journal, v.V, no.2 (May 1951), pp.64-69; Joseph L. Harsh, "Battlesword and Rapier: Clausewitz, Jomini, and the American Civil War," Military Affairs, December 1974, pp.133-138; Major [USAF] Francis S. Jones, "Analysis and Comparison of the Ideas and Later Influences of Henri Jomini and Carl von Clausewitz," Paper, Maxwell Air Force Base, AL: Air Command and Staff College, April 1985; Colonel [USA] Richard M. Swain, "`The Hedgehog and the Fox': Jomini, Clausewitz, and History," Naval War College Review, Autumn 1990, pp.98-109.

40. These points are most easily found in the bibliographical essay which opened the original French edition of the Summary, "Notice: sur la théorie actuelle de la guerre et sur son utilité" ("On the Present Theory of War and of Its Utility"). This essay is missing from (or severely edited in) most English language editions, although it is present in the 1854 American translation.

41. On Moltke, see Gunther E. Rothenberg, "Moltke, Schlieffen, and the Doctrine of Strategic Envelopment," in Paret, ed., Makers of Modern Strategy (1986), pp.296-325; Lieut.-Colonel F.E. Whitton, Moltke (New York: H. Holt, 1921); Daniel J. Hughes [USAF School for Advanced Airpower Studies, Maxwell Field, Al.], Moltke on the Art of War: Selected Writings (Presidio Press, 1995).

42. Grand [German] General Staff, trans. Commander (USN) A.G. Zimmerman, Moltke's Military Works: Precepts of War (Newport: Department of Intelligence and Research, U.S. Naval War College, 1935), Part II, p.1.

43. Quoted in Otto Pflanze, Bismarck and the Development of Germany, v.1 (Princeton: Princeton University Press, 1990), p.479.

44. E.g., William Manchester, The Last Lion: Winston Spencer Churchill (Boston: Little, Brown, 1988), v.2, 135: "If Clausewitz saw war as a science, the chancellor [Neville Chamberlain] saw it as a business...."

45. Carl von Clausewitz, tran. anonymous [Francis Egerton], The Campaign of 1812 in Russia (London: J. Murray, 1843), p.185. 

46. On War, Book Six, Chapter 1.

47. Clausewitz's approach has been connected to Plato, Kant, Fichte, and Hegel. See especially Paret, Clausewitz and the State, and W. B. Gallie, Philosophers of Peace and War: Kant, Clausewitz, Marx, Engels and Tolstoy (Cambridge: Cambridge University Press, 1978). Azar Gat, The Origins of Military Thought: From the Enlightenment to Clausewitz (Oxford: Oxford University Press, 1989), emphasizes the differing influences of the Enlightenment, Aufklärung, and Romantic intellectual movements. These connections are real but should not be over-stressed. Clausewitz was well (if largely self- ) educated and was certainly familiar with these writers, but the only philosopher to whom he made direct reference in On War was Montesquieu. Although On War's approach is essentially dialectical, overt references to any formal dialectical model rarely appear, and Clausewitz's approach is basically Platonic and appears closer to Fichte's than to Hegel's. Clausewitz's philosophical methods are his own and appear to be quite empirical in origin.

48. P.69 of H/P Princeton edition, in "The Note of 10 July 1827."

49. See Stephen J. Cimbala, Clausewitz and Escalation: Classical Perspective on Nuclear Strategy (London: Frank Cass, 1992), p.1-12.

50. On War presents the term "total war" only once, and that is as an example of something that doesn't happen: "This conception would be ineluctable even if war were total war, the pure element of enmity unleashed" (p.605 of H/P, Princeton edition).

51. My definitions; Clausewitz does not overtly distinguish between these two aspects of Politik. For my fullest discussion of this approach, see my working paper "Tiptoe Through the Trinity: The Strange Persistence of Trinitarian Warfare,"

52. For an example of the latter interpretation, see David Kaiser, Politics and War: European Conflict from Philip II to Hitler (Cambridge: Harvard University Press, 1990), p.415.

53. See for example Burton I. Kaufman, The Korean War: Challenges in Crisis, Credibility, and Command (New York: Knopf, 1986). Kaufman, p.150.

54. See Howard/Paret, eds., On War, fn., p.608. This editorial change was made (along with many others) by Marie's brother Fritz von Brühl. Bellinger discusses it on pp.225-26 of Marie von Clausewitz.

55. E.g., Arnold H. Price, "Clausewitz," Encyclopaedia Britannica, 15th ed. (1985).

56. Clausewitz, "Betrachtungen über einen künftigen Kriegsplan gegen Frankreich" (written c.1830), first published by the Historical Section of the General Staff as an appendix to Moltkes Militärische Werke, Teil I: Militärische Korrespondenz, Teil 4 (Berlin, 1902), pp.181-197.

57. On War, Book Eight, Chapter 2 (H/P p.581).

58. On War, H/P p.88.

59. Russell F. Weigley, "Military Strategy and Civilian Leadership," Klaus Knorr, ed., Historical Dimensions of National Security Problems (Lawrence: University Press of Kansas, 1976), 70, citing Gerhard Ritter, The Sword and the Scepter (Coral Gables: University of Miami Press, 1969-1973), v.1, p.65; cf. On War, Book One, Chapter 2.

60. On War, Book Eight, Chapter 2.

61. On War, Book One, Chapter 7.

62. On War, Book One, Chapter 4.

63. E.g., Colonel T.N. Dupuy [USA, ret.], Understanding War: History and Theory of Combat (New York: Paragon House, 1987).

64. Alan D. Beyerchen of Ohio State University was kind enough to let me read his then-unpublished paper, "Clausewitz, Nonlinearity, and the Unpredictability of War," International Security, Winter 1992/1993, pp.59-90, I have benefited deeply from his insights through his writings, his lectures, and many conversations ever since.

65. James Gleick, Chaos: Making a New Science (New York: Penguin, 1987), p.8.

66. On War, author's preface.

67. On War, Book Eight, Chapter 4. 

68. Note that the translation given here differs substantially from that on p.89 of the Howard/Paret translation, for reasons of grammar, clarity, and accuracy. For a thorough discussion, see my working paper "Tiptoe Through the Trinity: The Strange Persistence of Trinitarian Warfare." This working translation is based on comparisons among the first edition of Vom Kriege, the 1873 translation by J.J. Graham (London: N. Trübner, 1873); the O.J. Matthijs Jolles translation (New York: Random House, 1943); and the Howard/Paret 1984 edition; and on long-running consultations with Tony Echevarria, Alan D. Beyerchen, Jon Sumida, Gebhard Schweigler, and Andreas Herberg-Rothe. Obviously, I bear sole responsibility for the result.

69. The elements of the Trinity are enumerated here for the sake of clarity. There are no numbers in the original.

70. I.e., Book Two.

71. I owe this observation to Alan Beyerchen. For a creative misperception based on the use of the word "duel," see Michael Walzer, Just and Unjust Wars: A Moral Argument with Historical Illustrations (New York: Basic Books, 1977), fn, p.25.

72. See On War, Book One, Chapter 2, "Purpose and Means in War" and Book Three, Chapter 1.

73. My example, not Clausewitz's. 

74. On War, Book One, Chapter 2.

75. On War, Book Four, Chapter 11.

76. See esp. "On the Basic Question of Germany's Existence," in Clausewitz, Historical and Political Writings, pp.377-384.

77. On War, Book Three, Chapter 3.

78. As is pointed out by Jehuda L. Wallach, The Dogma of the Battle of Annihilation: The Theories of Clausewitz and Schlieffen and Their Impact on the German Conduct of Two World Wars (Westport, CT: Greenwood Press, 1986), pp.21-22.

79. Book One, Chapter 1, On War.

80. On War, Book Three, Chapter 8 (from the 1908 Graham/Maude version).

81. On War, Book Three, Chapter 9; Book Four, Chapter 8.

82. William McElwee, The Art of War from Waterloo to Mons (Bloomington: Indiana University Press, 1974), p.29: "Essentially their work was imitative, based on the profound studies of Carl von Clausewitz into the system and methods which had enabled Napoleon almost to subjugate the whole of Europe." McElwee was speaking of Scharnhorst and Gneisenau, Clausewitz's mentors, not his disciples.

83. For example, Bradley S. Klein, "The Politics of the Unstable Balance of Power in Machiavelli, Frederick the Great, and Clausewitz: Citizenship as Armed Virtue and the Evolution of Warfare" (Ph.D. dissertation [political science]: University of Massachusetts, 1984), sees the balance of power mechanism and the nation-state system as inevitably sources of war, a model "intolerable" given the total war experience and the existence of nuclear weapons.

84. On War, Book Six, Chapter 1.

85. It is impossible, of course, to draw a truly accurate picture of Clausewitz's readership. People like William Sloane of Rutgers University Press, Robert Hutchins (president of the University of Chicago), and possibly George Orwell, Nathaniel Wright Stephenson, and Carl Sandburg seem to have had some significant familiarity with his work. They might be total aberrations or the tip of some significant iceberg.

86. A false point also made frequently in print. See for example Joseph Caldwell Wylie [Rear Admiral, USN], Military Strategy: A General Theory of Power Control (New Brunswick, NJ: Rutgers, 1967), p.53.

87. Stephen L. Melton, The Clausewitz Delusion: How the American Army Screwed Up the Wars in Iraq and Afghanistan (A Way Forward). Minneapolis: Zenith Press, 2009.

88. Bernard Brodie often made puzzled references, e.g., in his closing essay in the Howard/Paret version of On War, "The Continuing Relevance of On War," 50, to the failure of modern military thought to incorporate and supersede Clausewitz, in the manner in which it has absorbed, say, Adam Smith's contribution to economics.


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