United Nations sent troops. Soviet Union, conveniently absent when the vote was taken! Image if East Germany invaded W. Germany...
N. Korea invaded S. Korea, with Stalin's approval, WITHOUT telling Chinese. That is the fact. The end result is back to the 38th paraelle line AND US has a limitaey base in S. Korea.
I wonder if N. Korea does it again (not unlikely), without telling Chinese (likely), and US and S. Korea defeats it (certainty), what would China do this time.