And there's the problem over there of the sex ratio. Because of their one-child policy, there are many more males than females as a result of selective abortion and infanticide of baby girls. Whenever a country has too many males to females, war is inevitable.
Is there historical prcedent for your blanket statement? Until the last decade or so, I can't think of any civilization/country that ever had more males than females in any statistically significant numbers. Selectively killing both unborn and newly born females is a recent phenomenon in China; it's a direct consequence of their "one child" policy.