Since nobody is going to be allowed to board the North Korean ship we strongly suspect is transporting weapons -- nukes included -- without permission, and they're not likely to give said permission, why don't we have the various allied navies "guide" the ship (in the same way fighter jets direct a smaller, weaker aircraft to an appropriate landing field when they go astray into restricted airspace) into Somali waters, as it were? We could wait for the Somali pirates to board them, then "come to the rescue" of the N. Korean ship, maybe even "accidentally" puncturing a hull in the process (or is that too much?)... two birds with one stone.
Okay, I know I'm getting into silly fantasy territory, but why can't we figure out a way for our enemies to screw each other, instead of having an administration just stand there and make a show of wringing its hands over nuclear proliferation among rogue nations? We had enough of hand-wringing with the last POTUS, and he actually seemed to care about it.