"Speak softly and carry a big stick"  is the best policy now.  Yet that thinking is an anathema to Donald J. Trump.  He already praised Kim Jong Un which no doubt encouraged this response. Oh well, if some more tweets can't remove this threat perhaps after  North Korea Donald J. Trump can "bomb into oblivion" others like Pakistan and India to also remove that nuclear threat from the globe (or maybe not). Read your history of combat operations on the Northern  Korean Peninsula towards the Yalu River  to appreciate the problem this presents..