It would seem to me that warfare is the worst way to solve the population crisis because wars must involves the destruction of existing capitals(Human capitals, mostly) and high opportunity cost(Delaying the introduction of television and other consumer technologies).
I wasn't in any way suggesting that warfare per se was related to my point. My point was that birth rates in America were very low during WWII due to men being off at war and incomes were astonishingly high, while at the same time there was little to spend it on, resulting in high savings rates. So this phenomenon of a growing economy and low birth rate has occurred before, right here in the USA. And the results of that -- the post-war boom time -- are generally looked upon as an idyllic time in America's past. So I don't see why this would be some kind of "problem" to do the same thing in China.
