China used to be a big supporter of North Korea, but all that has changed in recent years, not least when Kim Jong Un's pro-china uncle was fed to a pack of dogs.

There used to be a lot of aid going to North Korea from China, but I think that has pretty much dried up now, and I think they often don't send defectors from North Korea back if they're picked up in China any more.

I think they don't see it as a particularly useful ally any more, and have started to try to develop more of a relationship with South Korea.

If the current regime in NK falls I'm not even sure they would step in these days, as long as someone like the Americans weren't involved in instigating it.