What is the natural thing to do if you are the leader of a country with a surplus of men?
I would think war would be the thing to do if you have way more men than women and no prospects of keeping these men content.
China has been preparing for war for decades and the US has been standing by scratching our unmentionables while they have been doing it.
The problem is most of those men are getting long in the tooth to be used as cannon fodder in a war. 20 years ago They were of prime military age - not so much now. Median population age in China is 38.