The New York Times has a pretty decent piece on the thinking of the administration in announcing the new policy, and as I suspected yesterday, it is aimed primarily at North Korea and Iran. But the Times thinks the policy may be intended to influence the leadership, I doubt that it will have any effect on them. However, the people of Iran may be a different story. For those inclined to be disenchanted with the regime, the fact that Iran's nuclear program puts them in the cross hairs of a large nuclear arsenal may give extra energy to their opposition. In the long run, only regime change in Iran is going to produce lasting peace in the region. I hold out hope that the people of Iran will eventually topple a regime that is so antithetical to any aspirations of better material conditions.
The one part of the new policy that I disagree with is the decision not to develop any new nuclear weapons. New weapons designed to burrow deep into underground bunkers are needed to disrupt the nuke/chem/bio development capacity of rogue states. A credible threat to be able to shut down their programs is a necessary piece of nuclear deterrence.
Slate does a good job of explaining the issues as well.