I’d like to take a minute to respond to Dan’s thoughts below. I’d first make one minor addition, which is that Saudi Arabia actually has told Israel it can use its airspace for an attack. (That is, if you can believe the London Times.)
I’m glad to see you’re doing a little series on this, because I think your analysis is valid but incomplete. I agree that at this juncture, an Israeli attack — especially if not conducted with American help — would be unwise. You’ve highlighted the logistical challenges involved and the consequences. They are formidable.
American and Israeli policy is not static, though. Now that Iran has backed off from its agreement in Geneva, the sanctions track is getting under way again. Sanctions could be much more effective than we thought even a few months ago, given three developments:
1. The discovery (or rather, disclosure) of the Qom enrichment facility. It crystallized the urgency to change Iranian behavior, perhaps even on Russia.
2. Internal Iranian unrest. The people are unhappy with the regime, and their grievance will only rise if they feel that the regime has further isolated the country. The Iranian government responds well to pressure when they feel the regime’s survival is at stake.
3. Technical setbacks in uranium enrichment. The number of centrifuges in Natanz is down 20%, possibly due in part to Western sabotage. With the nuclear timeline running longer and the regime timeline possibly running shorter, the urgency for military action eases.
As a result, former skeptics of sanctions are a little more willing to give them a go:
Another administration official said that Israeli officials, while still publicly hinting that they might take military action against Iran’s nuclear facilities, “now feel that what’s happening in Iran makes the country vulnerable to real sanctions,” and might give Mr. Obama more time to persuade China and Russia to go along. A senior Israeli diplomat in Washington said that in back-channel conversations “Obama has convinced us that it’s worth trying the sanctions, at least for a few months.”
In other words, military action is not necessarily a favorable or unfavorable option by nature. It is currently an unfavorable option.

Firstly, as for the Times, if it’s in a British newspaper and you don’t see it corroborated anywhere else, I tend to treat it with a Seymour Hersh level of credibility. Especially if it’s about secret diplomacy in the Middle East…
Secondly, I am hoping to give the military option its proper context with posts on sanctions, soft regime change, and “engagement.” I would not say that because military options are unfavorable now, they will always be so. I would say that people are giving too much weight to the diplomatic rationale against force, but treating it as a credible option, and not enough consideration to the requirements of actually conducting one. Because military action is currently unfavorable, we have not considered whether it is particularly possible. The operational challenges to the military option are likely to increase if they change at all, given the longer the problem goes unsolved, the more nuclear sites Iran can build, the more it can upgrade its air defense, and the stronger Iran can make its retaliatory ability.
OK, sounds legit. It also gave me a chance to extol the renewed hope in sanctions.