There had to be something somewhere in all of them, in all of us, that loved it. Some dark, aggressive, masochistic side of us, racial perhaps, that makes us want to spray our blood in the air, throw our blood away, for some damned misbegotten ideal or other.
Whether the ideal is morally right or wrong makes no difference so long as the desire to fight for it remains in us. Fanatics willing to die for ideals.
It was territory, back when we were animals. Now that we have evolved into higher beings and learned to talk, territoriality has moved up a step higher with us, and become ideals.
We like it.
Cynical as it sounds, one is about led to believe that only the defeated and the dead really hate war.