"Did IQs just drop sharply while I was away?" - Ellen Ripley, "Aliens" (1986)
No, Japan knows the effects first hand, and have been trying everything they can do to strive off this scenario, but NK is an asshole and it looks like Trump just got knocked in the head with common sense, or he is really just a coward and liar who is planning on backing down, after his tough guy persona has been checked.
