are we a war-like people?

'member the baby boomers. big increase in population right after ww2. I was born after vietnam and believe there was a bulge there. we've been at war in iraq and afghanistan for 8 years or so, and even if it's not officially over, it's starting to feel over. and babies are popping out. i have 3 friends who are themselves or their wives are prego. so my question is - is the war/victory-defeat cycle ingrained into us and now part of our collective (ugh) reproductive cycle?