On War

by Carl von Clausewitz

A special means of security consists in the bodies of troops, both small and large, escorting convoys. First, the most extended positions are not sufficient to secure the lines of communication, and next, such an escort is particularly necessary when the general wishes to avoid a very extended position. Therefore, we find, in Tempelhof’s History of the Seven Years’ War, instances without end in which Frederick the Great caused his bread and flour waggons to be escorted by single regiments of infantry or cavalry, sometimes also by whole brigades. On the Austrian side we nowhere find mention of the same thing, which certainly may be partly accounted for in this way, that they had no such circumstantial historian on their side, but in part it is also to be ascribed just to this, that they always took up much more extended positions.

Having now touched upon the four efforts which form the foundation of a defensive that does not aim at a decision, and which are at the same time, altogether free upon the whole from all offensive elements, we must now say something of the offensive means with which they may become more or less mixed up, in a certain measure flavoured. These offensive means are chiefly:—

1. Operating against the enemy’s communications, under which we likewise include enterprises against his places of supply.

2. Diversions and incursions within the enemy’s territory.

3. Attacks on the enemy’s corps and posts, and even upon his main body, under favourable circumstances, or the threat only of such intention.

The first of these means is incessantly in action in all campaigns of this kind, but in a certain measure quite quietly without actually making its appearance. Every suitable position for the defender derives a great part of its efficacy from the disquietude which it causes the assailant in connection with his communications; and as the question of subsistence in such warfare becomes, as we have already observed, one of vital importance, affecting the assailant equally, therefore, through this apprehension of offensive action, possibly resulting from the enemy’s position, a great part of the strategic web is determined, as we shall again find in treating of the attack.

Not only this general influence, proceeding from the choice of positions, which, like pressure in mechanics, produces an effect invisibly, but also an actual offensive movement with part of the army against the enemy’s lines of communication, comes within the compass of such a defensive. But that it may be done with effect, the situation of the lines of communication, the nature of the country, and the peculiar qualities of the troops must be specially propitious to the undertaking.

Incursions into the enemy’s country which have as their object reprisals or levying contributions, cannot properly be regarded as defensive means, they are rather true offensive means; but they are usually combined with the object of a real diversion, which may be regarded as a real defensive measure, as it is intended to weaken the enemy’s force opposed to us. But as the above means may be used just as well by the assailant, and in itself is a real attack, we therefore think more suitable to leave its further examination for the next book. Accordingly we shall only count it in here, in order to render a full account of the arsenal of small offensive arms belonging to the defender of a theatre of war, and for the present merely add that in extent and importance it may attain to such a point, as to give the whole war the appearance, and along with that the honour, of the offensive. Of this nature are Frederick the Great’s enterprises in Poland, Bohemia and Franconia, before the campaign of 1759. His campaign itself is plainly a pure defence; these incursions into the enemy’s territory, however, gave it the appearance of an aggression, which perhaps had a special value on account of the moral effect.

An attack on one of the enemy’s corps or on his main body must always be kept in view as a necessary complement of the whole defence whenever the aggressor takes the matter too easily, and on that account shows himself very defenceless at particular points. Under this silent condition the whole action takes place. But here also the defender, in the same way as in operating against the communications of the enemy, may go a step further in the province of the offensive, and just as well as his adversary may make it his business to lie in wait for a favourable stroke. In order to ensure a result in this field, he must either be very decidedly superior in force to his opponent—which certainly is inconsistent with the defensive in general, but still may happen—or he must have a method and the talent of keeping his forces more concentrated, and make up by activity and mobility for the danger which he incurs in other respects.

The first was Daun’s case in the Seven Years’ War; the latter, the case of Frederick the Great. Still we hardly ever see Daun’s offensive make its appearance except when Frederick the Great invited it by excessive boldness and a display of contempt for him (Hochkirch, Maxen, Landshut). On the other hand, we see Frederick the Great almost constantly on the move in order to beat one or other of Daun’s corps with his main body. He certainly seldom succeeded, at least, the results were never great, because Daun, in addition to his great superiority in numbers, had also a rare degree of prudence and caution; but we must not suppose that, therefore, the king’s attempts were altogether fruitless. In these attempts lay rather a very effectual resistance; for the care and fatigue, which his adversary had to undergo in order to avoid fighting at a disadvantage, neutralised those forces which would otherwise have aided in advancing the offensive action. Let us only call to mind the campaign of 1760, in Silesia, where Daun and the Russians, out of sheer apprehension of being attacked and beaten by the king, first here and then there, never could succeed in making one step in advance.