Isn't that human evolution and/or survival however?
Before civilization flourished, humans formed tribes, acted warlike, etc. As things got better, the race got more civilized.
Even today, the most "warlike" and "tribal" regions of the earth tend to be where things are rotten and dangerous.
Perhaps the whole point is that the "tribal warlike" phase is a necessary, albeit evil, one in building a society from rubble.