Whilst it's not ideal that NK is a nuclear state then is it not just another nuclear state. Admittedly the man in charge isn't especially stable.
But surely he knows that if he attacks Guam/Hawaii/continental US then it will likely be the last thing he ever does? Presumably thats deterrence?
Maybe he doesn't care but I'm sure that Chinese/Japanese/South Koreans and everyone else will.
Trump is stuck between a rock and a hard place?