Given time, the fighting itself will cause the two sides to become more like each other, even to the point where opposites converge, merge, and change places. Weakness turns into strenght, strenght into weakness. The principal reason behind this phenomenon is that war represent perhaps the most imitative activity known to man, The whole secret of victory consists of trying to understand the enemy in order to outwit him. A mutual learning process ensues. Even as the struggle proceds, both sides adapt their tactical methods, the means they employ, and - most important of all - their morale to fit the opponent. Doing so, sooner or later the point will come where they are no longer distinguishable.
(...)
Over the long run no amount of pampering can make up for the fact that fighting the weak demeans those who engage in it and, therefore, undermines its own purpose. He who loses out to the weak loses; he who triumphs over the weak also loses. In such an enterprise there can be neither profit nor honor. Provided only the exercise is repeated often enough, as surely as night follows day the point will come when the enterprise collapses.

(Martin Van Creveld, The Transformation of War, 1991)

As one bitter joke had it, now that the IDF had overrun where the Katyusha were fired, it ought to go ahead and capture the place where they are made (presumably in the Ural Mountains).

(Martin Van Creveld, The Sword and the Olive, 1998)