The increase may not necessarily have been due to a greater number of killed and wounded or even to a greater loss of material, such as guns or ships; there may have been no increase in inequality in either of these ways, for the increase in inequality may have consisted in the fact that the weaker force was driven to a position less advantageous to it for conducting operations in the future.

But whatever the nature of the advantage gained by the stronger side, the result has been that the weaker side has come out of the battle relatively weaker than it was before.
For this reason, it is highly desirable to each side to win each battle.

This does not mean that the loss of any one battle by either party to a war means that the party losing that battle will necessarily lose the war; for many battles may be fought by such small portions of the whole nations' forces, or be lost by such small margins that the loss of one battle, or even several battles, may be retrieved; in fact, in few wars have the victories been all on one side.

It does mean, however, that each lost battle is a backward step; and that for this reason the effort must be that no battle shall be lost.
_Strategy and Tactics_ .-- Now, to win battles, two things combine, strategy and tactics.

The strategy of each side tries to arrange matters so that the forces on its side shall enter each battle with the greatest chance of victory; tactics tries to handle the forces with which it enters a battle in such a way that its side shall gain the victory.