Trouble with NK is, they don't have second strike capability, so a disarming first strike from the US is possible and NK knows that. That puts NK in a use it or

Trouble with NK is, they don't have second strike capability, so a disarming first strike from the US is possible and NK knows that. That puts NK in a use it or lose it situation with their nuclear weapons and it may be, that the regime calculates that they (the generals) can survive one. Or they don't, they calculate that their only chance is rapid escalation and basically calling the bluff of the US, or they may just prefer to go out with a bang rather than with a wimper. That means that the nuclear threshold for NK may be a lot sooner than it would be if they have second strike capability. And the US knows that, and knows that they may have to use a disarming first strike before NK decides it's only chance is rapid escalation. NK knows that the US knows. Toss twitter into the mix and you have a pretty toxic stew, even though nobody is actually very unhappy about the status quo.