The second question is how to act upon the enemy’s expenditure in strength, that is, to raise the price of success.

The enemy’s outlay in strength lies in the wear and Tear of his forces, consequently in the destruction of them on our part, and in the loss of provinces, consequently the conquest of them by us.

Here, again, on account of the various significations of these means, so likewise it will be found that neither of them will be identical in its signification in all cases if the objects are different.  The smallness in general of this difference must not cause us perplexity, for in reality the weakest motives, the finest shades of difference, often decide in favour of this or that method of applying force.  Our only business here is to show that, certain conditions being supposed, the possibility of attaining our purpose in different ways is no contradiction, absurdity, nor even error.

Besides these two means, there are three other peculiar ways of directly increasing the waste of the enemy’s force.  The first is invasion, that is the occupation of the enemy’s territory, not with A view to keeping it, but in order to levy contributions upon it, or to devastate it.

The immediate object here is neither the conquest of the enemy’s territory nor the defeat of his armed force, but merely to do him damage in A general way.  The second way is to select for the object of our enterprises those points at which we can do the enemy most harm.  Nothing is easier to conceive than two different directions in which our force may be employed, the first of which is to be preferred if our object is to defeat the enemy’s Army, while the other is more advantageous if the defeat of the enemy is out of the question.  According to the usual mode of speaking, we should say that the first is primarily military, the other more political.  But if we take our view from the highest point, both are equally military, and neither the one nor the other can be eligible unless it suits the circumstances of the case.  The third, by far the most important, from the great number of cases which it embraces, is the wearing out of the enemy.  We choose this expression not only to explain our meaning in few words, but because it represents the thing exactly, and is not so figurative as may at first appear.  The idea of wearing out in a struggle amounts in practice to A gradual exhaustion of the physical powers and of the will by the long continuance of exertion.