China has effectively taken the place of Cold war era Russia, competing for supremacy against US.

The difference between Cold-War time USSR & China is that, China has dispute with almost all of it's neighbors. Let's keep Taiwans right for independence aside, even well developed countries like Japan & South Korea have started fearing for China's expansionist one party regime. Both SoKo & Japan look towards US for their protection.

If US in future fails to guarantee the security of those, then it is very much possible that Japan & SoKo might decide to go Nuclear ...they have technology.