Of course there is a “do nothing” option!
In fact, that’s the option which enabled the cold war to end in peace, rather than pieces…..
The West will always have a sufficient Nuclear Arsenal to completely flatten NK, and NK knows it. Even if they develop their Nuclear Tech and methods of launching it, they cannot actually ever use it. It’s called Detente or MAD, which ever you favour. Ultimately NK are a small country on their own in the world, a Nuclear strike by them on any foreign power would open the door for a similar Nuclear retaliation by any number of foreign powers, or agents for those powers (ie NATO etc)
Does this not rely on common sense and concern for the citizens that they govern on the part of the leadership?
I can envisage various scenarios where MAD would not restrain the NK leadership