As someone who tried to think about this 44 years ago when the Ehrlichs' book, The Population Bomb, was published and when I read it at the ripe old age of 17, I will say that trying to outreproduce anyone seems particularly insane, given our stressed out resource base and scarcity of so much in the near future. Some of us would love to see the ancient forests remain and a bit of clean water remain drinkable.
Nonetheless, it is of interest to respond to these claims, backed up by 'research' done with highly flawed methodology in at least some cases. For instance, a world-famous study on the Yanomamo tribespeople--a particularly warlike hunter-gatherer society in Amazonia--purports to show that violence-committing males have more children than those who neglect to murder others. The astonishing omission from the discussion of validity of the study is that, on average, those males who hadn't committed murder were approximately a decade younger than the males who had killed someone. In any random population of human males younger than old age, obviously, a cohort of males some 10 years older will have more children. The Yanomamo study proves nothing about killing as a reproductive strategy (Fry, 2005).
This question is really only important insofar as the myth that war is inevitable and even desirable because we are driven to it by the evolutionary success of warring societies. There is just enough truth in that to be very dangerous indeed. It is reminiscent of Kurt Vonnegut's anecdote about another author asking him if Slaughterhouse Five was an antiwar novel (Ringler, 1993). When Vonnegut said yes, the fellow said, well, you might as well write an anti-glacier novel, by which he meant that war was just a force of nature, absolutely unavoidable (and now that a consuming war machine has helped to produce the global warming that is eradicating glaciers the irony is hard to miss).
We are in fact the best ever at amassing material goods, consumer items, and we have the huge homes, credit card debt, and storage facilities to prove it. We are awash in junk, degrading in every way. That, presumably, is success.
Here comes China. They manufacture everything and now finally outproduce the US in greenhouse gas, though the US still consumes more oil than any nation. Even though China has not been at war nearly as much as the US has, they certainly have out-reproduced the US, with almost four times the population. That is smart evolutionary strategy?
So what the war anthropologists are saying, presumably, is, have more war, have more children, and you have out-evolved those stupid peaceful ones. Thank goodness for the social scientists and peace researchers who have looked more deeply at these issues. Peace will prevail, as one organizer once told me, or it won't matter anyhow, because no one will be around to worry about it. Some day, in the not-so-distant future, we are going to have to relearn what the peaceful Stone Age tribes knew thousands of years ago, about how to live happily rather than so competitively, about how to relax and enjoy simple, beautiful pleasures rather than strive to make enough money to purchase the perennially elusive material possession that brings happiness, an illusion that endangers all of us, and being more warlike won't get anyone success in solving those problems.
Fry, D. P. (2005). The human potential for peace: An anthropological challenge to assumptions about war and violence. New York, NY: Oxford University Press.
Ghiglieri, M. P. (1999). The dark side of man: Tracing the origins of male violence. Reading, MA: Perseus.
McNeill, W. H. (1984). The pursuit of power. Chicago: The University of Chicago Press.
Ringler, Dick (Ed.) (1993). Dilemmas of war and peace: A sourcebook. Madison, WI: University of Wisconsin-Extension.