THERE is no theoretical idea in the art of war which has played such a part in criticism as that we are now entering upon. It is the "great war steed" in all accounts of battles and campaigns; the most frequent point of view in all arguments, and one of those fragments of scientific form with which critics make a show of learning. And yet the conception embodied in it has never yet been established, nor has it ever been clearly explained.
We shall try to ascertain its real meaning, and then see how far it can be made available for practical use.
We treat of it here because the defence of mountains, river defences, as well as the conceptions of strong and entrenched camps with which it closely connects itself, required to have precedence.
The indefinite confused conception which is concealed behind this ancient military metaphor has sometimes signified the most exposed part of a country at other times the strongest.
If there is any spot without the possession of which no one dare venture to penetrate into an enemy's country that may, with propriety, be called the key of that country. But this simple, though certainly at the same time also, barren notion has not satisfied theorists, and they have amplified it, and under the term key of a country imagined points which decide upon the possession of the whole country.
When the Russians wanted to advance into the Crimean peninsula, they were obliged to make themselves masters of the isthmus of Perekop and its lines, not so much to gain an entrance generally—for Lascy turned it twice (1737 and 1738)—but to be able to establish themselves with tolerable security in the Crimea. That is very simple, but we gain very little in this through the conception of a key-point. But if it might be said, Whoever has possession of the district of Langres commands all France as far as Paris—that is to say, it only rests with himself to take possession—that is plainly a very different thing, something of much higher importance. According to the first kind of conception the possession of the country cannot be thought of without the possession of the point which we have called key; that is a thing which is intelligible to the most ordinary capacity: but according to the second kind of conception, the possession of the point which we have called key, cannot be imagined without the possession of the country following as a necessary consequence; that is plainly, something marvellous, common sense is no longer sufficient to grasp this, the magic of the occult sciences must be called into requisition. This cabala came into existence in works published fifty years ago, and reached its zenith at the end of the last century; and notwithstanding the irresistible force, certainty and distinctness with which Buonaparte's method of conducting war carried conviction generally, this cabala has, nevertheless, still managed, we say, to spin out the thread of its tenacious existence through the medium of books.
(Setting aside for a moment our conception of the key-point) it is self-evident that in every country there are points of commanding importance, where several roads meet, where our means of subsistence may be conveniently collected, which have the advantage of being centrally situated with reference to other important points, the possession of which in short meets many requirements and affords many advantages. Now, if generals wishing to express the importance of such a point by one word have called it the key of the land, it would be pedantic affectation to take offence at their using that term; on the contrary we should rather say the term is very expressive and pleasing. But if we try to convert this mere flower of speech into the germ of a system branching out like a tree into many ramifications, common sense rises in opposition, and demands that the expression should be restricted to its true value.
In order to develop a system out of the expression, it was necessary to resort to something more distinct and absolute than the practical, but certainly very indefinite, meaning attaching to the term in the narrations of generals when speaking of their military enterprises. And from amongst all its various relations, that of high ground was chosen.
Where a road traverses a mountain ridge, we thank heaven when we get to the top and have only to descend. This feeling so natural to a single traveller is still more so in the case of an army All difficulties seem to be overcome, and so they are indeed in most instances; we find that the descent is easy, and we are conscious of a kind of feeling of superiority over any one who would stop us; we have an extensive view over the country, and command it with a look beforehand. Thus the highest point on a road over a mountain is always considered to possess a decisive importance, and it does in fact in the majority of cases, but by no means in all. Such points are very often described in the despatches of generals by the name of key-points; but certainly again in a somewhat different and generally in a more restricted sense. This idea has been the starting point of a false theory (of which, perhaps, Lloyd may be regarded as the founder); and on this account, elevated points from which several roads descend into the adjacent country, came to be regarded as the keypoints of the country—as points which command the country. It was natural that this view should amalgamate itself with one very nearly connected with it, that of a systematic defence of mountains, and that the matter should thus be driven still further into the regions of the illusory; added to which many tactical elements connected with the defence of mountains came into play, and thus the idea of the highest point in the road was soon abandoned, and the highest point generally of the whole mountain system, that is the point of the watershed, was substituted for it as the key of the country.
Now just at that time, that is the latter half of the preceding century, more definite ideas on the forms given to the surface of the earth through aqueous action became current; thus natural science lent a hand to the theory of war by this geological system, and then every barrier of practical truth was broken through, and reasoning floated in the illusory system of a geological analogy. In consequence of this, about the end of the eighteenth century we heard, or rather we read, of nothing but the sources of the Rhine and Danube. It is true that this nuisance prevailed mostly in books, for only a small portion of book wisdom ever reaches the real world, and the more foolish a theory the less it will attain to practice; but this of which we are now speaking has not been unproductive of injury to Germany by its practical effects, therefore we are not fighting with a windmill, in proof of which we shall quote two examples; first, the important but very scientific campaigns of the Prussian army, 1793 and 1794 in the Vosges, the theoretical key to which will be found in the works of Gravert and Massenbach; secondly, the campaign of 1814, when, on the principle of the same theory, an army of 200,000 men was led by the nose through Switzerland on to the plateau of Langres as it is called.
But a high point in a country from which all its waters flow, is generally nothing more than a high point; and all that in exaggeration and false application of ideas, true in themselves, was written at the end of the eighteenth and commencement of the nineteenth centuries, about its influence on military events, is completely imaginary. If the Rhine and Danube and all the six rivers of Germany had their common source on the top of one mountain, that mountain would not on that account have any claim to any greater military value than being suited for the position of a trigonometrical point. For a signal tower it would be less useful, still less so for a vidette, and for a whole army worth just nothing at all.
To seek for a key-position therefore in the so called key country, that is where the different branches of the mountains diverge from a common point, and at the highest source of its waters, is merely an idea in books, which is overthrown by nature itself, because nature does not make the ridges and valleys so easy to descend as is assumed by the hitherto so called theory of ground, but distributes peaks and gorges, in the most irregular manner, and not unfrequently the lowest water level is surrounded by the loftiest masses of mountain. If any one questions military history on the subject, he will soon convince himself that the leading geological points of a country exercise very little regular influence on the use of the country for the purposes of war, and that little is so over-balanced by other local circumstances, and other requirements, that a line of positions may often run quite close to one of the points we are discussing without having been in any way attracted there by that point.
We have only dwelt so long upon this false idea because a whole—and very pretentious—system has built itself upon it. We now leave it, and turn back to our own views.
We say, then, that if the expression, key-position, is to represent an independent conception in strategy, it must only be that of a locality the possession of which is indispensable before daring to enter the enemy's country. But if we choose to designate by that term every convenient point of entrance to a country, or every advantageous central point in the country, then the term loses its real meaning (that is, its value), and denotes something which may be found anywhere more or less. It then becomes a mere pleasing figure of speech.
But positions such as the term conveys to our mind are very rarely indeed to be found. In general, the best key to the country lies in the enemy's army; and when the idea of country predominates over that of the armed force, some very specially advantageous circumstances must prevail. These, according to our opinion, may be recognised by their tending to two principal results: first, that the force occupying the position, through the help of the ground, obtains extraordinary capability of tactical resistance; second, that the enemy's lines of communication can be sooner effectively threatened from this position than he can threaten ours.