1.—Division.
In strategy we must never ask what is to be the strength of a division or a corps, but how many corps or division an army should have. There is nothing more unmanageable than an army divided into three parts, except it be one divided into only two, in which case the chief command must be almost neutralised.
To fix the strength of great and small corps, either on the grounds of elementary tactics or on higher grounds, leaves an incredibly wide field for arbitrary judgment, and heaven knows what strange modes of reasoning have sported in this wide field. On the other hand, the necessity of forming an independent whole (army) into a certain number of parts is a thing as obvious as it is positive, and this idea furnishes real strategic motives for determining the number of the greater divisions of an army, consequently their strength, whilst the strength of the smaller divisions, such as companies, battalions, etc., is left to be determined by tactics.
We can hardly imagine the smallest independent body in which there are not at least three parts to be distinguished, that one part may be thrown out in advance, and another part be left in rear: that four is still more convenient follows of itself, if we keep in view that the middle part, being the principal division, ought to be stronger than either of the others; in this way, we may proceed to make out eight, which appears to us to be the most suitable number for an army if we take one part for an advanced guard as a constant necessity, three for the main body, that is a right wing, centre and left wing, two divisions for reserve, and one to detach to the right, one to the left. Without pedantically ascribing a great importance to these numbers and figures, we certainly believe that they represent the most usual and frequently recurring strategic disposition, and on that account one that is convenient.
Certainly it seems that the supreme direction of an army (and the direction of every whole) must be greatly facilitated if there are only three or four subordinates to command, but the commander-in-chief must pay dearly for this convenience in a twofold manner. In the first place, an order loses in rapidity, force, and exactness if the gradation ladder down which it has to descend is long, and this must be the case if there are corps-commanders between the division leaders and the chief; secondly, the chief loses generally in his own proper power and efficiency the wider the spheres of action of his immediate subordinates become. A general commanding 100,000 men in eight divisions exercises a power which is greater in intensity than if the 100,000 men were divided into only three corps. There are many reasons for this, but the most important is that each commander looks upon himself as having a kind of proprietary right in his own corps, and always opposes the withdrawal from him of any portion of it for a longer or shorter time. A little experience of war will make this evident to any one.
But on the other hand the number of divisions must not be too great, otherwise disorder will ensue. It is difficult enough to manage eight divisions from one head quarter, and the number should never be allowed to exceed ten. But in a division in which the means of circulating orders are much less, the smaller normal number four, or at most five, may be regarded as the more suitable.
If these factors, five and ten, will not answer, that is, if the brigades are too strong, then corps d’armée must be introduced; but we must remember that by so doing, a new power is created, which at once very much lowers all other factors.
But now, what is too strong a brigade? The custom is to make them from 2,000 to 5,000 men strong, and there appear to be two reasons for making the latter number the limit; the first is that a brigade is supposed to be a subdivision which can be commanded by one man directly, that is, through the compass of his voice: the second is that any larger body of infantry should not be left without artillery, and through this first combination of arms a special division of itself is formed.
We do not wish to involve ourselves in these tactical subtilties, neither shall we enter upon the disputed point, where and in what proportions the combination of all three arms should take place, whether with divisions of 8,000 to 12,000 men, or with corps which are 20,000 to 30,000 men strong. The most decided opponent of these combinations will scarcely take exception at the mere assertion, that nothing but this combination of the three arms can make a division independent, and that therefore, for such as are intended to be frequently detached separately, it is at least very desirable.
An army of 200,000 men in ten divisions, the divisions composed of five brigades each, would give brigades 4,000 strong. We see here no disproportion. Certainly this army might also be divided into five corps, the corps into four divisions, and the division into four brigades, which makes the brigade 2,500 men strong; but the first distribution, looked at in the abstract, appears to us preferable, for besides that, in the other, there is one more gradation of rank, five parts are too few to make an army manageable; four divisions, in like manner, are too few for a corps, and 2,500 men is a weak brigade, of which, in this manner, there are eighty, whereas the first formation has only fifty, and is therefore simpler. All these advantages are given up merely for the sake of having only to send orders to half as many generals. Of course the distribution into corps is still more unsuitable for smaller armies.
This is the abstract view of the case. The particular case may present good reasons for deciding otherwise. Likewise, we must admit that, although eight or ten divisions may be directed when united in a level country, in widely extended mountain positions the thing might perhaps be impossible. A great river which divides an army into halves, makes a commander for each half indispensable; in short, there are a hundred local and particular objects of the most decisive character, before which all rules must give way.
But still, experience teaches us, that these abstract grounds come most frequently into use and are seldomer overruled by others than we should perhaps suppose.
We wish further to explain clearly the scope of the foregoing considerations by a simple outline, for which purpose we now place the different points of most importance next to each other.
As we mean by the term numbers, or parts of a whole, only those which are made by the primary, therefore the immediate division, we say.
1. If a whole has too few members it is unwieldy.
2. If the parts of a whole body are too large, the power of the superior will is thereby weakened.
3. With every additional step through which an order has to pass, it is weakened in two ways: in one way by the loss of force, which it suffers in its passage through an additional step; in another way by the longer time in its transmission.
The tendency of all this is to show that the number of co-ordinate divisions should be as great, and the gradational steps as few as possible; and the only limitation to this conclusion is, that in armies no more than from eight to ten, and in subordinate corps no more than from four or at most six, subdivisions can be conveniently directed.