I though Zakaria had a pretty good summation of the situation in an interview on CNN
recently (try to ignore the cheesy/creepy profile pic...)
Basically, he's saying that if you look at the situation in its simplest form, there are really only two choices from which any and all policy decisions will flow - 1) either it is totally unacceptable for Iran to have nukes, or, 2) we need to figure out how to live with Iran having nukes. I know that's nothing profound, but sometimes the best place to start is with a simple decision based in realism rather than worked up emotion/anger/fear/whatever.
If the answer is #1, then we (as in, hopefully, the international community) are going to have to somehow assert influence on Iran, diplomatically or militarily - influence they have made clear they don't want, and that they will undoubtedly portray to the rest of the region as yet more unwelcome Western meddling trying to dictate the future of the Middle East. Given the current political/social climate in the region, this perspective will probably find a lot of resonance with a lot of people who are already fed up with Western aggression and dictation of what they can and can't do. Now we can argue the validity of that or not from our perspective, but at a certain point, that's moot if that's the way they see it regardless. This could be stronger diplomatic actions, which may work, or may not. In order to succeed, they would need to be shrewd diplomatic actions to aid in turning more Iranian public sentiment against the ruling theocracy of the country. The risk is that it backfires, and the ruling theocracy gets more public support because the public feels that their government is being unfairly persecuted.
These same risks become greatly
magnified if any military action were taken, and the likelihood of it turning more public support against us (both in Iran and the region in general) becomes much more likely. It's very easy to say, "we should just bomb the fuck out of them," but I really think this would be totally disastrous for us in many different ways, unless we already had a very broad coalition of support for such an action, and even better if it wasn't the US taking the lead on it for a change (it would be great to see European countries step up, since this would seriously affect them as well...). Still, I think any military action against Iran would be extremely risky, to put it mildly.
If we choose answer #2, then are we opening the floodgates for more nuclear proliferation throughout the region and the world? While N. Korea may be a recent exception, in most cases where a country has gained nuclear technology (Pakistan, for example), we've let them. Personally, I think that in the case of Pakistan, this was a crazy allowance, probably as much or more so than Iran, but we allowed it, much to India's dismay. Israel is undoubtedly of the position that it is completely unacceptable for Iran to have nukes, and I might feel differently if I lived within striking range of Iranian missiles too. It also dramatically shifts the balance of power in the region, and takes away the "ace in the hole" that Israel has enjoyed having. I have no sympathy for Israel these days, to be honest, but the likelihood for escalating conflict in the region between two countries that bitterly hate each other, and which both have nukes, seems extremely dangerous. So allowing Iran to continue on the path it's on seems to hinge on Iran being open to regulation/supervision like other nuclear countries, and to being a more cooperative world player in terms of diplomacy. Then again, in many ways the same could be said of recent actions by the US, if you were to look at it from a non-US perspective, but that's another discussion. Either way, we need to make sure Iran realizes, and truly buys into the maxim that, "With great power comes great responsibility." If they don't, then we will unfortunately need a Plan B, and it won't be pretty.