The success of the attack is the result of a present superiority of
force, it being understood that the moral as well as physical forces
are included. In the preceding chapter we have shown that the power of
the attack gradually exhausts itself; possibly at the same time the
superiority may increase, but in most cases it diminishes. The
assailant buys up prospective advantages which are to be turned to
account hereafter in negotiations for peace; but, in the meantime, he
has to pay down on the spot for them a certain amount of his military
force. If a preponderance on the side of the attack, although thus
daily diminishing, is still maintained until peace is concluded, the
object is attained. There are strategic attacks which have led to an
immediate peace but such instances are rare; the majority, on the
contrary, lead only to a point at which the forces remaining are just
sufficient to maintain a defensive, and to wait for peace. Beyond that
point the scale turns, there is a reaction; the violence of such a
reaction is commonly much greater than the force of the blow. This we
call the culminating point of the attack. As the object of the attack
is the possession of the enemy’s territory, it follows that the advance
must continue till the superiority is exhausted; this cause, therefore,
impels us towards the ultimate object, and may easily lead us beyond
it. If we reflect upon the number of the elements of which an equation
of the forces in action is composed, we may conceive how difficult it
is in many cases to determine which of two opponents has the
superiority on his side. Often all hangs on the silken thread of
imagination.
Everything then depends on discovering the culminating point by the
fine tact of judgment. Here we come upon a seeming contradiction. The
defence is stronger than the attack; therefore we should think that the
latter can never lead us too far, for as long as the weaker form
remains strong enough for what is required, the stronger form ought to
be still more so.