1) McArthurs: If McArthur attacked and finished off NK, sure we might have heightened the Cold War, but the USSR (now russia) wouldn't have attacked us back with nukes. We might have been able to take out communism from the Koreas.
coming back into present day, we wouldn't have a puny country trying to make nuclear missiles to shoot at us and having propaganda about how bad america is. If McArthur had his way, Korea may not be the way it is now
(but then that was how fate wanted it)
hope this helps
