Can we back up and just recognize how insane North Korea is? I think that future generations will look back on our history and wonder why nobody ever did anything about the incredible atrocities that took place in that country for decades.
It will definitely go down as one of the biggest failures of mankind. Especially since it was so easily preventable if MacArthur was permitted to just take the whole peninsula.
China was already sending troops and material to the front lines when MacArthur was ordered to stand down. Pushing further would have meant a hot war with China.
A hot war with China in 1950 was going to end quickly with the firepower USA had on-hand.
There is no way we could match them in numbers on the ground. Such a conflict would have inevitably led to us nuking them as a result. Which is probably the reason decision makers chose not to.
And maybe that's really the humanitarian failure. That USA didn't nuke China in 1950 or 1951. Would have solved a lot of problems for generations of people.