Now how is that precise moment to be described?
If a certain artificial formation and cohesion of an Army is the principal condition under which the bravery of the troops can gain a victory, as was the case during a great part of the period of the modern Art of War, then the breaking up of this formation is the decision. A beaten wing which is put out of joint decides the fate of all that was connected with it. If as was the case at another time the essence of the defence consists in an intimate alliance of the Army with the ground on which it fights and its obstacles, so that Army and position are only one, then the conquest of an essential point in this position is the decision. It is said the key of the position is lost, it cannot therefore be defended any further; the battle cannot be continued. In both cases the beaten Armies are very much like the broken strings of an instrument which cannot do their work.
That geometrical as well as this geographical principle which had a tendency to place an Army in a state of crystallising tension which did not allow of the available powers being made use of up to the last man, have at least so far lost their influence that they no longer predominate. Armies are still led into battle in a certain order, but that order is no longer of decisive importance; obstacles of ground are also still turned to account to strengthen a position, but they are no longer the only support.
We attempted in the second chapter of this book to take a general view of the nature of the modern battle. According to our conception of it, the order of battle is only a disposition of the forces suitable to the convenient use of them, and the course of the battle a mutual slow wearing away of these forces upon one another, to see which will have soonest exhausted his adversary.
The resolution therefore to give up the fight arises, in a battle more than in any other combat, from the relation of the fresh reserves remaining