For most of history, this concept of just war was rarely observed. The capacity of human beings to think up new ways to kill one another proved inexhaustible, as did our capacity to exempt from mercy those who look  different or pray to a different God. Wars between armies gave way to wars between nations - total wars in which the distinction between combatant and civilian became blurred. In the span of thirty years, such carnage would twice engulf this continent. And while it is hard to conceive of a cause more just than the defeat of the Third Reich and the Axis powers, World War II was a conflict in which the total number of civilians who died exceeded the number of soldiers who perished.