I think that the debate is fine and no amount of subjective sophistry on the part of the pro peace side of the argument can change the ever increasing facts that support the other.
We have even now recently discovered how many of these small societies of hunter gatherers were often part of larger groups that would make primitive ritual sites built at the confluence of their conjoined territories. They frequently banded together to fight outsiders along the migration routes of their big game herds. Conditions naturally developed in the environment that made war unavoidable (IE population growth/rescource aquisition/etc) at least from the perspective of those who made it. So far when viewed objectively warfare was much more prevalent then the new age we love peace so much crowd wants to see.
It shows every sign of being a natural process of evolution. One that may or may not be alleviated as we gradually synthesize ourselves in the future (provided what science so far predicts our future to look like happening the way they see it). And if we do go into the stars and encounter other civilizations, I am guessing it's just as likely that the same evolutionary process will be at work there as well.