We have proved, in the twelfth and thirteenth chapters, that in strategy a successive resistance is inconsistent with the nature of the thing, and that all forces available should be used simultaneously.
As regards forces which are moveable, this requires no further demonstration; but when we look at the seat of war itself, with its fortresses, the natural divisions of the ground, and even the extent of its surface as being also elements of war, then, these being immovable, we can only either bring them gradually into use, or we must at once place ourselves so far back, that all agencies of this kind which are to be brought into activity are in our front. Then everything which can contribute to weaken the enemy in the territory which he has occupied, comes at once into activity, for the assailant must at least blockade the defender’s fortresses, he must keep the country in subjection by garrisons and other posts, he has long marches to make, and everything he requires must be brought from a distance, etc. All these agencies commence to work, whether the assailant makes his advance before or after a decision, but in the former case their influence is somewhat greater. From this, therefore, it follows, that if the defender chooses to transfer his decision to a point further back, he has thus the means of bringing at once into play all these immovable elements of military force.
On the other hand, it is clear that this transfer of the solution (on the part of the defender) does not alter the extent of the influence of a victory which the assailant gains. In treating of the attack, we shall examine more