1946: Make sure that Henry Wallace was on FDRs Ticket as vice president.
Iran and Korea: Iran might be a threat to Israel, but North Korea really isn't a threat at all. I think the United States would turn North Korea into a parking lot if they dared use atomic weapons. Everyone who has them is terrified of using them, and there are many countries that do. The best example I can give you is India and Pakistan. They regularly go to war, but neither would dare use their atomic weapons on the other.
