Brad, you note below that Ahmadinejad's power is waning and the country's supreme leader Ali Khamenei appears to be reasserting control over foreign policy. You take this development as evidence that "Iran is much like any other country, with its own concerns and political disputes, not just single-mindedly obsessed with the destruction of Israel and the West."
But for that to be right, you would have to show that Khamenei is significantly less committed to Israel's destruction than Ahmadinejad. And that isn't true. In 1998, Khamenei called Israel a "cancerous growth." In 2000, he said "this cancerous tumor of a state should be removed from the region." Last summer, he described Israel as a "satanic and cancerous presence and an infected tumor for the entire world of Islam." He has also argued that "The Palestinian issue is not an internal Israeli matter. It involves the interests of the whole Islamic world, including Iran. All should strive to return that piece of land to Islamic hands."
As plenty of others have noted (see this TNR Online piece), Ahmadinejad isn't exactly the only member of the Iranian regime who would like to see Israel destroyed. Even a so-called moderate, former president Ali Akbar Hashemi-Rafsanjani, famously said, of a nuclear attack against Israel, "It is not irrational to contemplate such an eventuality." So maybe it's true that Khamenei is taking power back from Ahmadinejad. But that isn't really evidence that the Iranian regime is any less committed to Israel's destruction.
None of this means that I think America should bomb Iran. Nor does it mean that Israel should bomb Iran. There are plenty of good reasons to worry that either of those options would carry prohibitive risks. And, Brad, you may be right that the best way to prevent the Iranians from getting nuclear weapons is for the United States to simply talk to them. Still, I can't help but be a little disturbed by the cavalier attitude some liberals have taken towards the prospect of a nuclear Iran--a cavalier attitude that they often justify with the observation that Ahmadinejad doesn't really hold the reins of power in his own country. (To take just one example, here's Juan Cole describing the Iranian threat last year: "Ahmadinejad is really a millenarian who believes the second coming of the Mahdi is around the corner, which would be worrying if he was really in charge, but that's not the case.")
I confess to having no idea what we should do about Iran, but I will say this: If I were Israeli, I would be terrified of Iran getting a nuclear weapon. As an American Jew, I am terrified on Israel's behalf. And the apparent decline of Ahmadinejad's personal power doesn't strike me as a particularly good reason to be any less worried.