On War

by Carl von Clausewitz

The conclusion we draw, therefore, is that however easy an attack on a convoy may appear in its tactical aspect, still it has not much in its favour on strategic grounds, and only promises important results in the exceptional instances of lines of communication very much exposed.

CHAPTER XIX.
Attack on the Enemy’s Army in its Cantonments

We have not treated of this subject in the defence, because a line of cantonments is not to be regarded as a defensive means, but as a mere existence of the army in a state which implies little readiness for battle. In respect to this readiness for battle, we therefore did not go beyond what we required to say in connection with this condition of an army in the 13th chapter of the 5th book.

But here, in considering the attack, we have to think of an enemy’s army in cantonments in all respects as a special object; for, in the first place, such an attack is of a very peculiar kind in itself; and, in the next place, it may be considered as a strategic means of particular efficacy. Here we have before us, therefore, not the question of an onslaught on a single cantonment or a small corps dispersed amongst a few villages, as the arrangements for that are entirely of a tactical nature, but of the attack of a large army, distributed in cantonments more or less extensive; an attack in which the object is not the mere surprise of a single cantonment, but to prevent the assembly of the army.

The attack on an enemy’s army in cantonments is therefore the surprise of an army not assembled. If this surprise succeeds fully, then the enemy’s army is prevented from reaching its appointed place of assembly, and, therefore, compelled to choose another more to the rear; as this change of the point of assembly to the rear in a state of such emergency can seldom be effected in less than a day’s march, but generally will require several days, the loss of ground which this occasions is by no means an insignificant loss; and this is the first advantage gained by the assailant.

But now, this surprise which is in connection with the general relations, may certainly at the same time, in its commencement, be an onslaught on some of the enemy’s single cantonments, not certainly upon all, or upon a great many, because that would suppose a scattering of the attacking army to an extent which could never be advisable. Therefore, only the most advanced quarters, only those which lie in the direction of the attacking columns, can be surprised, and even this will seldom happen to many of them, as large forces cannot easily approach unobserved. However, this element of the attack is by no means to be disregarded; and we reckon the advantages which may be thus obtained, as the second advantage of the surprise.

A third advantage consists in the minor combats forced upon the enemy in which his losses will be considerable. A great body of troops does not assemble itself at once by single battalions at the spot appointed for the general concentration of the army, but usually forms itself by brigades, divisions, or corps, in the first place, and these masses cannot then hasten at full speed to the rendezvous; in case of meeting with an enemy’s column in their course, they are obliged to engage in a combat; now, they may certainly come off victorious in the same, particularly if the enemy’s attacking column is not of sufficient strength, but in conquering, they lose time, and, in most cases, as may be easily conceived, a corps, under such circumstances, and in the general tendency to gain a point which lies to the rear, will not make any beneficial use of its victory. On the other hand, they may be beaten, and that is the most probable issue in itself, because they have not time to organise a good resistance. We may, therefore, very well suppose that in an attack well planned and executed, the assailant through these partial combats will gather up a considerable number of trophies, which become a principal point in the general result.

Lastly, the fourth advantage, and the keystone of the whole, is a certain momentary disorganisation and discouragement on the side of the enemy, which, when the force is at last assembled, seldom allows of its being immediately brought into action, and generally obliges the party attacked to abandon still more ground to his assailant, and to make a change generally in his plan of operations.

Such are the proper results of a successful surprise of the enemy in cantonments, that is, of one in which the enemy is prevented from assembling his army without loss at the point fixed in his plan. But by the nature of the case, success has many degrees; and, therefore, the results may be very great in one case, and hardly worth mentioning in another. But even when, through the complete success of the enterprise, these results are considerable, they will seldom bear comparison with the gain of a great battle, partly because, in the first place, the trophies are seldom as great, and in the next, the moral impression never strikes so deep.

This general result must always be kept in view, that we may not promise ourselves more from an enterprise of this kind than it can give. Many hold it to be the non plus ultra of offensive activity; but it is not so by any means, as we may see from this analysis, as well as from military history.