War and violence are not part of being human, otherwise we wouldn't have had 2 million years of relative peace during prehistory. The "violent" nature of humanity is a product of the social and material structure in which humanity lives (as is all behaviour). The hunter-gatherer lifestyle didn't require war.
If humanity manages to create a sufficiently stable society, the same thing can happen. We have to be able to guarantee people's basic needs in order for it to work though, which is the issue Capitalism has caused.
Why is "violence" necessary? Even if it is "a part of nature", so is rape -- does this mean rape is good and necessary?
As a human being with a moral code, I would never do any sort of unprompted aggression towards others under any circumstance.
Millions still starve, millions still fight in unjust wars, millions eat themselves into diabetic heart disease ridden coffins, millions live in bombed out hellholes over flags and ideologies that lost all meaning decades ago. The materialists have the most violent, destructive, and brutal wars in all of human history under their belt. You need science to develop the atom bomb and you need a ridiculous and childish relying on science to abuse it. Simple as. Science alone leads to nothing but disaster and ruin.
Nobody thinks the world is doing good right now. If they do theyre laughed at, and for good reason.