The nature-nurture question determines whether ending mass violence is even conceivable.

Evidence

These historical events are relevant to a key question that social scientists have long confronted, namely whether political violence is natural and endemic to the human condition or whether it is the result of specific historical, social, and cultural conditions. If mass violence is part of human nature, then the best we can hope for is to uncover methods of intervention that will keep it to a minimum. If, on the other hand, organized aggression is the result of socially constructed forces, then it is at least theoretically plausible to imagine eliminating it altogether. — John T. Jost and Jim Sidanius, Political Psychology, 154