What I think is actually going on that you might not hear about in the news

China and Russia are waiting for North Korea or Trump to make a fatal mistake. At this point they could do several different things.

1. They could do nothing and let North Korea and the U.S. fight it out while they study how the U.S. destroys North Korea and then use this information against the U.S. at a later date.

2. They could feign almost anything because there is nothing they have to do at all except watch the U.S. and North Korea go at it.

Or
3. They could say "Hey! This war is spilling over into China so we are going to fight against North Korea and South Korea and take over the whole peninsula away from the U.S., South Korea, and the free world.

(if there is anything left of it).
Or
4. They might just use it as an excuse to get rid of the U.S. which has been a thorn in their side all along.

But,
5. Maybe Trump has already been paid by Putin and Xi to end democratic institutions in the U.S. and Europe so they won't have to nuke us but instead economically destroy us instead.