Почему войны становятся неизбежным злом?

Since ancient times, not a single power has openly proclaimed the need for the destruction of other peoples or tribes, speaking only about the pacification of ungrateful or evil neighbors, whose peoples will be better off under the auspices of other rulers - just and honest, and they will certainly establish proper order. And the order was sometimes brought about in such a way that not a single person remained of a whole series of peoples.