Korean War goes nuclear -1950/1951
I've been trying unsuccessfully to find answers to what would've occurred had Douglas MacArthur gotten the green light to nuke cities in China in 1950-1951. (He was very headstrong over the matter and President Truman was able to head him off. He was upset over the crossing of the Yalu and the Chinese invasion of N. Korea.)
Some background: Douglas MacArthur, WWII war hero, taker of risks, and occasional disobeyer of orders (and also the guy who ordered the Inchon landing amidships in Korea) wanted to poison an enormous area in China with radioactive cobalt, as well as explode "nucular" weapons in Chinese cities. He said that he didn't expect the Soviet Union to pounce. Truman sacked MacArthur for "insubordination" after MacArthur argued with him, and MacArthur got a ticker-tape parade and made his famous Old Soldiers Never Die speech. If Truman had been less edgy... or if MacArthur had been more dictatorial (note: he overhauled Japan after WWII with an American-style democratic constitution, so I don't think being absolute tyrant was really in his bloodstream), then MacArthur might've attempted to play around with the Bomb. I doubt that he'd succeed with the cobalt (it's too deadly to work with).