There is some doubt if General MacArthur ever actually advocated dropping the A-Bomb in the Korean War. There is evidence, however, that he recommended employing nuclear waste as a barrier between the warring factions. As sort of a "what if": how do you think things would have played out if the US did drop the atomic bomb on the peninsula? Would the Soviets have responded in kind? Would it have sparked World War III or would cooler heads prevailed? Anyway, I thought it would make for an interesting discussion.
If nukes were dropped during the Korean War, the Soviets might have launched attack on the west side in Europe as retaliation. Massive soviet army would have been able to take over entire continent Europe in short notice. Yes, in short it would have started WWIII for sure.