The US nearly lost the Korean war.
The US army was nearly overrun at least once.
The US airforce never achieved air superiority, and Soviet aircraft were better in most ways.
The only undisputed advantage the US had was nukes, which is why MacArthur wanted to use them tactically (!)
I'm far from convinced that using nukes in the Korean War would've been a good move, but equating it with "kill[ing] them all" is completely dishonest. What's your goal in this debate, and is it served by dishonest rhetoric?
> That USA didn't nuke China in 1950 or 1951. Would have solved a lot of problems for generations of people.
> USA dropping nukes probably would have been the better outcome for humanity.
Both of which I read as an expansive campaign of "nuking China"