Hell yes, unless it turned in to ww3 and even then the UN forces might be able to force the Chinese and Russians into a stalemate.
But who has more nukes, and Naval superiority? the UN does of course. Maybe B-47 raids on Beijing, Vladivostok, and Port Arthur?
I don't know if the Americans managed to push the Koreans back China and the Soviets would almost certainly get involved and then it would likely go nuclear.
I really doubt that. Seriously, why would Russia throw the whole world onto the fire over NK? Unless the UN is crazy enough to invade Russian territory, I doubt nukes would be involved....
Any full out nuclear is improbable until about the 60s. In 1950, the US had over 298 nukes, while the Soviets had...3True but that could lead to a Soviet invasion of Europe with possible Germany,France and the US West Coast being hit by soviet nukes if America were to use Nukes in Europe.
This could be a very bad scenario for Eurasia.