This is the ultimate result of pretending to be working toward nuclear disarmament, while in actuality building our own supply of nuclear missiles and subs and bombers. 
If it is perfectly ok for a nation, say the US, or Israel for that matter, to have such weapons of mass destruction, aimed at pretty much anyone, then it is ok for other nations to build their own defense network. 
It is our fault, and this has been coming for a long, long time. 
Self defense is the highest requirement for a government, to defend its people. 
I carry no water for North Korea, but it is immoral to be so hypocritical as to say only the US and some other countries get to swagger about the world scene with giant weapons. Nuclear disarmament will never happen in my lifetime, but really, if we support Israel and its hundreds of nuclear missiles and bombs aimed at its enemies, then how do we tell anyone not to have the same defense?
Hugh Massengill, Eugene Oregon