I don't think that whether or not the US has an interest in occupation is a large factor in this risk. If the US attacked China, China would respond, guaranteed

I don't think that whether or not the US has an interest in occupation is a large factor in this risk. If the US attacked China, China would respond, guaranteed. That would lead to a full-on war. Unless the US backed down, a nuclear attack by one side or another doesn't seem unlikely enough.