nostr:npub1tdsdk6l08hvq9q7737gm42c3fyq5xgqmy4lpvmda5hqaemhkhhzqz6djq2 China is a nuclear power, so there’s not much they can do in that regard.
Quite frankly, the Norks have shown the way forward. They have a limited nuclear program, and they play nice with both Russia and China, and use the interplay between them and their usefulness against the US to keep their independence. Japan has a lot more leeway, but also a lot more at stake. I doubt rushing nukes would make anyone happy. 
Their economic strength is really their biggest asset, but between financial fuckery, and potential damage from something like sanctions, they need more. The Japanese fleet is very strong regionally. If they had nukes and a more independent financial position, they could sit pretty on their island, a lot like the UK.