IF an army sets out on any expedition, whether it be to attack the enemy and his theatre of war, or to take post on its own frontier, it continues in a state of necessary dependence on the sources from which it draws its subsistence and reinforcements, and must maintain its communication with them, as they are the conditions of its existence and preservation. This dependence increases in intensity and extent in proportion to the size of the army. But now it is neither always possible nor requisite that the army should continue in direct communication with the whole of its own country; it is sufficient if it does so with that portion immediately in its rear, and which is consequently covered by its position. In this portion of the country then, as far as necessary, special depôts of provisions are formed, and arrangements are made for regularly forwarding reinforcements and supplies. This strip of territory is therefore the foundation of the army and of all its undertakings, and the two must be regarded as forming in connection only one whole. If the supplies for their greater security are lodged in fortified places, the idea of a base becomes more distinct; but the idea does not originate in any arrangement of that kind, and in a number of cases no such arrangement is made.
But a portion of the enemy's territory may also become a base for our army, or, at least, form part of it; for when an army penetrates into an enemy's land, a number of its wants are supplied from that part of the country which is taken possession of; but it is then a necessary condition that we are completely masters of this portion of territory, that is, certain of our orders being obeyed within its limits. This certainty, however, seldom extends beyond the reach of our ability to keep the inhabitants in awe by small garrisons, and detachments moving about from place to place, and that is not very far in general. The consequence is, that in the enemy's country, the part of territory from which we can draw supplies is seldom of sufficient extent to furnish all the supplies we require, and we must therefore still depend on our own land for much, and this brings us back again to the importance of that part of our territory immediately in rear of our army as an indispensable portion of our base.
The wants of an army may be divided into two classes, first those which every cultivated country can furnish; and next those which can only be obtained from those localities where they are produced. The first are chiefly provisions, the second the means of keeping an army complete in every way. The first can therefore be obtained in the enemy's country; the second, as a rule, can only be furnished by our own country, for example men, arms, and almost all munitions of war. Although there are exceptions to this classification in certain cases, still they are few and trifling, and the distinction we have drawn is of standing importance, and proves again that the communication with our own country is indispensable.
Depôts of provisions and forage are generally formed in open towns, both in the enemy's and in our own country, because there are not as many fortresses as would be required for these bulky stores continually being consumed, and wanted sometimes here, sometimes there, and also because their loss is much easier to replace; on the other hand, stores to keep the army complete, such as arms, munition of war, and articles of equipment are never lodged in open places in the vicinity of the theatre of war if it can be avoided, but are rather brought from a distance, and in the enemy's country never stored anywhere but in fortresses. From this point, again, it may be inferred that the base is of more importance in relation to supplies intended to refit an army than in relation to provisions for food.
Now, the more means of each kind are collected together in great magazines before being brought into use, the more, therefore, all separate streams unite in great reservoirs, so much the more may these be regarded as taking the place of the whole country, and so much the more will the conception of a base fix itself upon these great depôts of supply; but this must never go so far that any such place becomes looked upon as constituting a base in itself alone.
If these sources of supply and refitment are abundant, that is, if the tracts of territory are wide and rich, if the stores are collected in great depôts to be more speedily brought into use, if these depôts are covered in a military sense in one way or another, if they are in close proximity to the army and accessible by good roads, if they extend along a considerable width in the rear of the army or surround it in part as well—then follows a greater vitality for the army, as well as a greater freedom in its movements. Attempts have been made to sum up all the advantages which an army derives from being so situated in one single conception, that is, the extent of the base of operations. By the relation which this base bears to the object of the undertakings, by the angle which its extremities make with this object (supposed as a point), it has been attempted to express the whole sum of the advantages and disadvantages which accrue to an army from the position and nature of its sources of supply and equipment; but it is plain this elegant piece of geometrical refinement is merely a play of fancy, as it is founded on a series of substitutions which must all be made at the expense of truth. As we have seen, the base of an army is a triple formation in connection with the situation in which an army is placed: the resources of the country adjacent to the position of the army, the depôts of stores which have been made at particular points, and the province from which these stores are derived or collected. These three things are separated in space, and cannot be collected into one whole, and least of all can we substitute for them a line which is to represent the width of the base, a line which is generally imagined in a manner perfectly arbitrary, either from one fortress to another or from one capital of a province to another, or along a political boundary of a country. Neither can we determine precisely the mutual relation of these three steps in the formation of a base, for in reality they blend themselves with each other always more or less. In one case the surrounding country affords largely the means of refitting an army with things which otherwise could only be obtained from a long distance; in another case we are obliged to get even food from a long distance. Sometimes the nearest fortresses are great arsenals, ports, or commercial cities, which contain all the military resources of a whole state, sometimes they are nothing but old, feeble ramparts, hardly sufficient for their own defence.
The consequence is that all deductions from the length of the base of operations and its angles, and the whole theory of war founded on these data, as far as its geometrical phase, have never met with any attention in real war, and in theory they have only caused wrong tendencies. But as the basis of this chain of reasoning is a truth, and only the conclusions drawn are false, this same view will easily and frequently thrust itself forward again.
We think, therefore, that we cannot go beyond acknowledging generally the influence of a base on military enterprises, that at the same time there are no means of framing out of this maxim any serviceable rules by a few abstract ideas; but that in each separate case the whole of the things which we have specified must be kept in view together.
When once arrangements are made within a certain radius to provide the means of subsisting an army and keeping it complete in every respect, and with a view to operations in a certain direction, then, even in our own country, this district only is to be regarded as the base of the army; and as any alteration of a base requires time and labour, therefore an army cannot change its base every day, even in its own country, and this again limits it always more or less in the direction of its operations. If, then, in operating against an enemy's country we take the whole line of our own frontier, where it forms a boundary between the two countries as our base, we may do so in a general sense, in so far that we might make those preparations which constitute a base anywhere on that frontier; but it will not be a base at any moment if preparations have not been already made everywhere. When the Russian army retreated before the French in 1812, at the beginning of the campaign the whole of Russia might have been considered as its base, the more so because the vast extent of the country offered the army abundance of space in any direction it might select. This is no illusory notion, as it was actually realised at a subsequent time, when other Russian armies from different quarters entered the field; but still at every period throughout the campaign the base of the Russian army was not so extensive; it was principally confined to the road on which the whole train of transport to and from their army was organised. This limitation prevented the Russian army, for instance, from making the further retreat which became necessary after the three days' fighting at Smolensk in any direction but that of Moscow, and so hindered their turning suddenly in the direction of Kaluga, as was proposed in order to draw the enemy away from Moscow. Such a change of direction could only have been possible by having been prepared for long beforehand.
We have said that the dependence on the base increases in intensity and extent with the size of the army, which is easy to understand. An army is like a tree. From the ground out of which it grows it draws its nourishment; if it is small it can easily be transplanted, but this becomes more difficult as it increases in size. A small body of troops has also its channels, from which it draws the sustenance of life, but it strikes root easily where it happens to be; not so a large army. When, therefore, we talk of the influence of the base on the operations of an army, the dimensions of the army must always serve as the scale by which to measure the magnitude of that influence.
Further it is consistent with the nature of things that for the immediate wants of the present hour the subsistence is the main point, but for the general efficiency of the army through a long period of time the refitment and recruitment are the more important, because the latter can only be done from particular sources while the former may be obtained in many ways; this again defines still more distinctly the influence of the base on the operations of the army.
However great that influence may be, we must never forget that it belongs to those things which can only show a decisive effect after some considerable time, and that therefore the question always remains what may happen in that time. The value of a base of operations will seldom determine the choice of an undertaking in the first instance. Mere difficulties which may present themselves in this respect must be put side by side and compared with other means actually at our command; obstacles of this nature often vanish before the force of decisive victories.