Japan has said that if North Korea goes nuclear, they will too, in self defense.
China goes into meltdown at the thought of a nuclear Japan. They remember WWII.
China has complete control of North Korea if they chose to use it. If China closes the border, The lights go off in North Korea, the vehicles stop moving, and everyone starves to death within a few weeks.
I think China likes to see the West squirm as long as possible, but in the end, they will squash Kim one way or the other.
So9
You're right.