There comes a point where you have to either walk the walk or shut up. North Korea is doing their level best to provoke an incident but we're not biting. This is exactly the right course of action. They want to draw us into a confrontation but are getting angry because we are not responding to their provocations and it is driving them nuts. There is only so far they can go with this trash talk.
Time is on our side, not theirs. They have no food, money or resources and are getting really desperate. Let them dangle in the breeze for a little longer and enjoy their communist utopia.
It seems that way to me too, but you have to wonder why. What does NK stand to gain? Seems to me they have everything to lose.