I wouldn't worry about North Korea launching massive war against South Korea. Research what North & South Korea have aimed at each other - both could annihilate the other's capital city within an hour. Even if Kim Jong Un is batshit crazy off-the-wall & orders a war, the N Korean military highest-ups won't allow it (the military generals would arrange for a "suicide" of Kim Jong Un from "excessive grief"). If anything happens N Korea will attack a small S. Korean or Japanese target, threaten total nuclear annihilation if retaliation is used, then when no massive retaliation takes place N Korea will use that as propaganda of how afraid the world is of them. . . same ole song.