Mark Steyn called this out in his book “America Alone”. He said soon there will be no more Germans (because of their low reproduction rate) then Fench and Italians and the rest of Western Europe, then Japan, Then China (because of its one-child policy).
The native U.S. is still reproducing itself but the influx of Central Americans is gaining on us.
Its an interesting situation. I would not put China n the same category as Japan or Western Europe. You have to remember that China has 1.37B people—imagine if that number doubled or tripled? The implications for that on China and its neighbors would be staggering. Western Europe does have a big demographic problem (as do white people in general).
China could easily solve much of its problem by permitting city dwellers to have two children. Or permit the rural groups who want more kids to have a third if they can pay for it.