In truth - while NK regards the US as its enemy. They will never ever be a military threat to the US.
The mistake is that the region has far too long relied on the US for assistance with deescalating the threat while the US has no real stakes in the game. The idea that a bomb from half way across the world will successfully land on SF, LA, or Chicago is pretty unlikely. Hawaii and Alaska are possibly targets, but given the example of Japan and Pearl Harbor - I dont think NK will attack, if ever, a non-major city.
Tokyo and Seoul however, are potentially 5-10 minutes away from annihilation. But at least for Seoul, thats status quo. Curious how the Japanese will get involved