- If there is one or if there are several fortresses near the frontier, then the great question arises, whether the defender should seek an action before or behind them. The latter recommends itself—
a, by the superiority of the enemy in numbers, which forces us to break his power before coming to a final struggle.
b, by these fortresses being near, so that the sacrifice of territory is not greater than we are compelled to make.
c, by the fitness of the fortresses for defence.
One principal use of fortresses is unquestionably, or should be, to break the enemy’s force in his advance and to weaken considerably that portion which we intend to bring to an engagement. If we so seldom see this use made of fortresses, that proceeds from the cases in which a decisive battle is sought for by one of the opposing parties being very rare. But that is the only kind of case which we treat of here. We therefore look upon it as a principle equally simple and important in all cases in which the defender has one or more