China has a history of really sucking at border conflicts.
If China and America work together—this Korean War II will not last a week. The Chinese will put a puppet general in charge and we will send aid to rebuild the stricken land. North and South Korea can start working together. Who ever is put in as the new dictator will be sane and North Korea will become a better place to live—maybe even become a tourist attraction in a few years. Did you know they have a Great Wall that was built to keep out the huns? Impressive as the Chinese wall—but it was in the north—could be a good tourist attraction in the future. This is the best case against kings —you sometimes get a murderous nut case on the throne.