"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones." -Albert Einstein
I mostly agree with Fred Kaplan that the recent missile test by North Korea consists of nothing more than their usual "hey look at me!!!" Because they don't have oil supplies to threaten cutting off, their only real method of international attention from free states is to lob a couple large pieces of steel into the lower atmosphere with the pretenses that said steel could in the future contain nuclear material.
What is interesting about North Korea developing nukes is the same thing that makes a nuclear-armed Iran interesting: it poses little or no direct threat to the United States. Although there are several nations now that are nuclear armed, only a couple have ICBM capability, that is, the ability to launch a nuke from Siberia and have it detonate in New York. The most distant enemy Iran could strike would be Israel. The most distant enemy that North Korea could strike is probably no one. Possibly Japan, but doubtful.
However, China has expressed before that they don't like their underlings in the South Sea to get mischievous, and it'll be interesting to see how China responds to any increasing jabs by North Korea. Best we just stay out of this one and let the Commies sort it out amongst themselves.