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:—
- Operating against the enemy’s communications, under which we likewise include enterprises against his places of supply.
- Diversions and incursions within the enemy’s territory.
- 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.