Its true that US military did not respect Chinese military and its ability before Korean War. And to win in Korea, US can only win by taking the battle to China. As US was not willing to do that, its fortunate that Korea was divided today.US was the superior force with advance technology, largest air cover and naval power during Korea war. Korea situated by the surrounding ocean only N.K border with China. The surround water in Korea allowed U.N naval force to reenforce their front line with fire power and air raid on Chinese army penetration. With no air force or naval force, Chinese army without heavy artillery managed to push U.N force back to the 38 parallel was the major victory in it self. Imagine if China have the air cover and naval power of the U.S, Korea would be unite under N.K government. This is the fact that, China great strategist halted U.S intention of unified Korea and divide Korea into South and North Korea as today.