The Chinese dont want to take them out and in fact the Chinese take up for the train thieves in the UN.
You've got to think about North Korea as China's little brother who always needs to be bailed out of jail at 3 AM.
Likewise, China is the former gangster who's gone legit, and doesn't like his old past brought up.
North Korea embarrasses China, but they're family. Big Brother China keeps telling little brother North Korea to straighten out, but the advice doesn't seem to work.