Here is the thing,China had massive starvation periods in their history and their population No. were part of the reason. Their present Govt has eliminated much of this and tries to reduce a certain amount of "mouth to feed." They have not engaged in frivolous warfare so this is not an effective way to control your own population either.
If for one reason or other the Chinese want or need a larger population they will not hesitate to open the tap.
The One child rule isn't new and women have every opportunity to terminate an unwanted or illegal pregnancy as early as detected. It is those that wish to ignore that provision that when found out are dealt with harshly as are all lawbreakers in China.
BTW there are minority racial groups within China that are exempt from the One child rule.
Applying your laws/morals ethics to other jurisdictions isn't useful IMO.
