I think Iran believes that allah will keep them safe, and that NK's chia pet believes he is safe, both because he's been told he's sooooooo wonderful for soooooo long that he actually believes it, and that his proximity to China and Japan (as well as his ability to shell Seoul into a gravel pit) protect him.
None of the above players is immune from thinking they can find a cat's paw to do the deed, and suffer the consequences, while they hide behind the uncertainty of the ultimate source and diplomacy.
They are safe as long as they don't use these weapons against the US. I lived two years in Iran. The Iranians are not suicidal and want to live as much as we do. The security surrounding Kim Jong-il is immense. He wants to live as much as you do.
None of the above players is immune from thinking they can find a cat's paw to do the deed, and suffer the consequences, while they hide behind the uncertainty of the ultimate source and diplomacy.
That is the real danger, i.e., giving nuclear weapons to non-state actors that cannot be easily traced back to the source. The Chinese, North Koreans, Iranians, or any other potential hostile nuclear power could do the same. We need to revise our doctrinal response to take such an event into consideration and how we would retaliate. Under today's calculus, none of our potential enemies would ever launch an overt nuclear attack against the US. They would be committing national suicide and they know it.