What we are talking about here is the Chinese building a fleet of new aircraft carriers. The US is waning and collapsing internationally and immaterial to the discussion at hand. Thought we were talking about what will happen in the future, not the past.
China’s main concern, in the past and in the future, has always been and will always be to stave off the perpetual threat of internal disintegration while maintaining independence from foreign domination.
Japan’s navy alone is superior to the Chinese navy, carriers or not. Carriers are a horrible investment anyway and it has almost no experience operating them.
Japan, South Korea and Taiwan could go nuclear any time they wish; India and Russia already possess a nuclear deterrent; and China is surrounded by populous nations who all have common cause in not being dominated by them.
The only foreign territory which China can credibly be said to have designs on is the Russian Far East, and that’s the Russians’ problem, not ours. It has no amphibious capability to speak of.
China is only our problem if we make it so, and there’s really no good reason to make it so.
Worrying about China is a waste of time and energy.