NK doesnt have a missle that can touch the US.
I wasn't referring to NK. It's not like Kim would nuke us anyways. He's a sociopath, and sociopaths are afraid to die, so he wouldn't nuke us as death would be a sure thing for him. Not to mention that missile range isn't a factor. It's not like Bin Laden launched giant air-plane shaped missiles from Afganistan.
All I'm saying, it's good to know for the possibility that a nuclear weapon falls into the hands of a terrorist with a strong enough will to smuggle it into the US.