It is very likely that there has always been war. Those have been documented even between chimpanzees and those fights absolutely were lethal. https://en.m.wikipedia.org/wiki/Gombe_Chimpanzee_War

I always felt like the fact that you get attacked by local fauna when you cause pollution was a comment on that. As in the planet recognises that you are not doing a good thing.

Love me some good old fachwerkhäusers