The demographics are not a problem because of how they constrain the number of troops they can field - their population is still quadruple the US, so no problem

The demographics are not a problem because of how they constrain the number of troops they can field - their population is still quadruple the US, so no problems there. The problem is the economic weakness that comes with a country where each working person supports two retired people (either directly as in family or indirectly as in taxes). That doesn't work as far as we know. So China is right near the peak of their power (maybe 15-30 years away.) I still think that means they'll be patient and wait for their moment. But they can't wait forever.