Well technically we did destroy the north, they only reason 23 million people live in oppression in the north right now is because of the damn Chinese.
True, but the U.S was the largest force there, and a U.S general was in charge of all the U.N forces.
Uh not really, they pushed us back a hundred or so miles at the cost of 600,000 men. The only reason they were able to do this is because the U.S military was scraped after ww2, China had the logistical advantage, and they vastly out numbered us. Had the U.S military been at its ww2 strength we very well could have taken China like MacArthur wanted.
Even with all those advantages they still only managed to scrape a draw. And like you said
Also remember the Soviets were rendering our air power ineffective because the U.S was still using ww2 planes, while the Soviets had jets.
You only listed commonwealth victories, i feel compelled to link American victories. 
I would say the U.N forces beat the shit out China and South Korea, the only real victories they had was the initial surprise attack.
