It is therefore very plain how different will be the relations of two armies according as it is by the first or the second of the above ways, that they arrive at that point which may be regarded as the end of the assailant’s course.
This is merely the result of the mutual destruction; to this must now be added the reductions which the advancing party suffers otherwise in addition, and respecting which, as already said, we refer to the seventh book; further, on the other hand, we have to take into account reinforcements which the retreating party receives in the great majority of cases, by forces subsequently joining him either in the form of help from abroad or through persistent efforts at home.
Lastly, there is, in the means of subsistence, such a disproportion between the retreating side and the advancing, that the first not uncommonly lives in superfluity when the other is reduced to want.
The army in retreat has the means of collecting provisions everywhere, and he marches towards them, whilst the pursuer must have everything brought after him, which, as long as he is in motion, even with the shortest lines of communication, is difficult, and on that account begets scarcity from the very first.
All that the country yields will be taken for the benefit of the retreating army first, and will be mostly consumed. Nothing remains but wasted villages and towns, fields from which the crops have been gathered, or which are trampled down, empty wells, and muddy brooks.
The pursuing army, therefore, from the very first day, has frequently to contend with the most pressing wants. On taking the enemy’s supplies he cannot reckon; it is only through accident, or some unpardonable blunder on the part of the enemy, that here and there some little falls into his hands.