War is Not Inevitable

There are people who believe war is inevitable. It is in our nature, rooted in the more primitive, ancient aspects of our makeup and cannot be overcome. The territorial imperative. We are animals after all - and these instincts so deep, so ingrained we cannot hope to control them.
Comforting thoughts for those who have killed in war or for those trying to make sense of what is in the end  completely senseless - war. Comforting thoughts -  but untrue nonetheless.
The primitive brain from which  our more basic reflexes and drives come from represents about 7% of the entire brain by volume. The more highly evolved cerebral cortex - where higher order thought processes occur - massively dwarfs it. We are not ruled by our primitive brain. It is not the seat of evil and temptation that eventually wears us down to face the 'truth' about our aggressive natures and makes war inevitable.  It is our cerebral cortex that evolved to make us human. The more primitive aspects of our brain contribute to who and what we are but it is our cerebral cortex that makes us human, gives us sentience, and the ability to permanently avoid war and self-destruction if we so choose.