I don’t think Trump needs to act at all.
Fat Kimmy picks one of our strategic locations, Guam, that is located far enough south that a missile track couldn’t possibly be mistaken for a shot toward the U.S. No sense getting vaporized by accident, eh?
Then he threatens to launch not one but FOUR missiles toward the island. Why four? Because he can ratchet up the rhetoric sequentially, getting louder with each launch, all in hopes of getting the ($$$) goodies he so desperately needs. Also, each successive launch MIGHT be the real one, forcing Mr. Trump to consider a shoot-down.
Sounds to me like Kimmy is just screaming for someone to take him seriously and nobody will.