The Coming Confrontation With North Korea - Start of WWIII?

With a madman, Kim Jong-un, running North Korea into the ground and completely out of control(even China seems to have little influence), it seems that a confrontation with the U.S. is inevitable. North Korea has just tested an ICBM capable of hitting most of the U.S. and it is just a matter of time before these missles are armed with nuclear warheads. Trump has stated that he will not let this continue and Jong-un has promised to retaliate if the U.S. strikes. This probably means retaliation agains't South Korea, possibly Japan, and U.S. warships in the area. Watch the video below and then comment on what the U.S/Trump should do, if anything.