I think North Korea, is having a field day with US president Trump threats of unleashing a rain of fire and fury. His statements were very irresponsible . Saying that Korea has been misbehaving was probably the stupidest thing he said, and blaming past administration for allowing N Korea's bad misbehaviors.
And “irresponsible” because it sounds like Trump shooting his mouth off again. Maybe his national security team approved of that kind of language, but it sounds a lot like what Trump does on Twitter, which is shooting his mouth off and saying stuff and his national security people have to walk it back in the next couple of days.