Maybe, maybe not. The Soviet’s first (successful) atomic ballistic missile test was in 1949, exactly one year before the Korean War. China had theirs in 1964. They were at that moment in time far behind the USA.
... okay? Unless your plan is to follow that up with an invasion of both the Soviet Union and China, that doesn't fucking change my point? Normalizing the use of nuclear weapons to achieve political goals at the very start of the Cold War is not going to result in a less tense environment for the possibility of nuclear exchanges between nuclear powers.
Now we have to deal with the USA, Russia, and China all pointing nukes at each other and sabre rattling. North Korea literally launches ballistic missiles into the ocean as a method of threatening Japan.
And how would glassing the Chinese border have changed any of this except for North Korea?