“In addition, China gets 85% of their oil from the Persian Gulf. That could be blockaded by the US, Japan, or India and China couldn’t do anything about it unless they wanted to go nuclear.”
This is the key point. China cannot project power into the India Ocean. Japan and the US can.
OTOH, the clock is ticking on China. Demographic crash is already happening. Their access to high end electronics is now extremely restricted. The leadership may think that their only way to stay in power is to start a war and break thru the first island chain. But suppose they succeed. That doesn’t fix demographics.
LOL. At 1.35 billion they have about 300,000,000 military aged males. Maybe more.