Back in high school, one of the most enjoyable debate topics was that nuclear weapons are immoral–if I recall correctly, the category error was part of the resolution. Two simplistic assumptions were typically made which have probably warped my sense of the issue: that the use of nuclear weapons between two actual nuclear powers would involve near absolute destruction for both of them, and that all nuclear powers would be equal in their, uh… “nuclearity.” The first assumption was occasionally challenged by someone who argued that the destruction effected by nuclear weapons was continuous with what could be done by conventional means (i.e. Dresden).
With those points in mind, I’ll note that there’s an old but fascinating post about how the United States has nuclear superiority with respect to Russia and China, and that this fact may actually make our situation with respect to them more dangerous rather than less. Also, it appears that the North Koreans probably have no more than a dozen nuclear warheads, whereas we have thousands.
Finally, onwards to the point: if what happened in North Korea is in anyway representative, it raises the question of how seriously we should take Iran’s nuclear ambitions. It goes without saying that it should be a top foreign policy priority of the United States to avoid a nuclear-armed Iran. However, given the slow state of the Iranian nuclear weapons process, it seems that the risks of war with Iran (even just aerial strikes, as Podhorrez has proposed) would be too high to undergo, given the threat.
Side note: This debate topic was one of the only ones which provided an occasion to apply one’s knowledge of calculus. People often made the claim that nuclear war would create an “infinite harm.” In one round, a fellow responded by claiming that deterrence would reduce the chance of such a war to zero, and then exclaimed that “infinity times zero is still zero!” Sadly, while everyone on my team was familiar with calculus, this guy’s opponent wasn’t, and the round missed the chance for an XKCD moment.