Surely you have heard that the Chinese sometime perform forced abortions on some women who are found to be breaking this law
If government performs forced abortions - that is a bad thing - and civilized countries should not do that.
But I see nothing wrong in population growth control - If my government can try to boost it - Chinese can try to reduce it (forced abortions are not the only way).
Globally population control is needed, because in last ten years world population grew by 1 billion.
And after 10 years there will be another one billon.
But world resources are running out and are becoming more expensive.

Western Europe is not a problem, because there population growth rate already is low or negative:
Population growth rate by country - Thematic Map - World

The Most IMPORTANT Video You'll Ever See (part 1 of - YouTube

I would say that it is OK for Chinese to have 3-5 percent of population
How about 30-50 and Chinese as official language?