Clarification of what DPRK has done

North Korea evidently does not have a thermonuclear weapon. They have an atomic bomb. There are large differences. The weapons currently in the US arsenal need a bomb the size of the one dropped on Hroshima just as a fuse to set them off. A fission bomb works by detonating TNT around fisiable material. The fissionable atoms break and realease its engery. A thermonuclear bomb uses an atom bomb to cause its nuclear material to fuse. This creates enormous heat hence the term thermo. The fusion bombs we have are basically small Suns that we can start. They are thousands of times more destructive than the DPRK's little bomb. They are overkill made flesh. This is not to diminish the problem caused by the DPRK testing their fire cracker. If you can build an atom bomb you are not too far from building a super-bomb.

DPRK's Bomb estimated at: 15,000 tons of TNT

Us bombs: 100,000,000 tons of TNT or about 7,500 times more powerful than the DPRK's bomb