But there still remains a most important point to be noticed. In a partial combat, the force required to obtain a great result can be approximately estimated without much difficulty, and, consequently, we can form an idea of what is superfluous. In Strategy this may be said to be impossible, because the strategic result has no such well-defined object and no such circumscribed limits as the tactical. Thus what can be looked upon in tactics as an excess of power, must be regarded in Strategy as a means to give expansion to success, if opportunity offers for it; with the magnitude of the success the gain in force increases at the same time, and in this way the superiority of numbers may soon reach a point which the most careful economy of forces could never have attained.
By means of his enormous numerical superiority, Buonaparte was enabled to reach Moscow in 1812, and to take that central capital. Had he by means of this superiority succeeded in completely defeating the Russian Army, he would, in all probability, have concluded a peace in Moscow which in any other way was much less attainable. This example is used to explain the idea, not to prove it, which would require a circumstantial demonstration, for which this is not the place.(*)
(*) Compare Book vii., second edition, p. 56.
All these reflections bear merely upon the idea of a successive employment of forces, and not upon the conception of a reserve properly so called, which they, no doubt, come in contact with throughout, but which, as we shall see in the following chapter, is connected with some other considerations.
What we desire to establish here is, that if in tactics the military force through the mere duration of actual employment suffers a diminution of power, if time, therefore, appears as a factor in the result, this is not the case in Strategy in a material degree. The destructive effects which are also produced upon the forces in Strategy by time, are partly diminished through their mass, partly made good in other ways, and, therefore, in Strategy it cannot be an object to make time an ally on its own account by bringing troops successively into action.
We say on “its own account,” for the influence which time, on account of other circumstances which it brings about but which are different from itself can have, indeed must necessarily have, for one of the two parties, is quite another thing, is anything but indifferent or unimportant, and will be the subject of consideration hereafter.