Barring such rare occasions, contests in war have usually been between two forces spread over considerable areas of land or water; and the contest has usually been decided by the defeat of one of the two. If in any individual combat, all the forces possessed by both sides had been engaged, and if either force had been annihilated, the entire war between the two parties would have been decided. This was nearly the case in the naval battle off Tsushima between the Russian and Japanese fleets--and the treaty of peace was signed soon after. Usually, however, neither party to the quarrel has had all its forces on the field in any one battle, and neither force in the battle has been annihilated. Usually, only partial forces have been engaged, and only partial victories have been won; with the result that wars between contending nations have usually consisted of a series of battles, with intervals of rest between. If two opposing forces in any battle were exactly equal in fighting power, neither side in any battle would gain a victory, the two sides would inflict identical amounts of damage on each other, and the two sides would end the battle still equal in force. At rare intervals, such conditions have been approximated; but usually one side has had more fighting power than the other, and has inflicted more damage of various kinds than it has received, with the result that it attained an advantage more or less important over the other, and with the further result that the original disproportion between the two forces was increased. 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.