I'm actually quite serious.  

An FAE (Fuel Air Explosive) on the North Korean Assembly while Kim was addressing them would certainly be 'overkill' but perfectly legal under the laws of war and leave only lower-ranked members of the fourth largest Army in the world to discuss the aftermath.   With their 'diety' and the top echelons of their military gone, those discussions could be viable.

A more targeted strike, as we tried several times against both Qadaffi and Saddam Hussein, could be as effective, of course.