Bill Kristol and Jamie Fly don't see too many:
Yet if we carried out a targeted campaign against Iran’s nuclear facilities, against sites used to train and equip militants killing American soldiers, and against certain targeted terror-supporting and nuclear-enabling regime elements, the effects are just as likely to be limited.
It’s unclear, for example, that Iran would want to risk broadening the conflict and creating the prospect of regime decapitation. Iran’s rulers have shown that their preeminent concern is maintaining their grip on power. If U.S. military action is narrowly targeted, and declared to be such, why would Iran’s leaders, already under pressure at home, want to escalate the conflict, as even one missile attack on a U.S. facility or ally or a blockade of the Strait would obviously do?
While I personally don't think starting a third war in the Greater Middle East is the best idea at the moment, it's perfectly possible that should the U.S. hit Iranian facilities, Iran would simply fold up and do nothing. But it seems that if the U.S. wants to start a military campaign against Iran it needs to be ready to contemplate the need for wider action if Iran decides to retaliate. To simply assert that Iran will be deterred from the cost of escalation isn't really sufficient because the U.S. has to be ready to impose those costs if Iran does decide to escalate - is that something the American people are ready for?
UPDATE: Discussing this with Kevin offline, he raised another, more consequential point: if the Iranian regime is so concerned about their survival that they won't hit the U.S. after a military strike against their country, then they obviously aren't going to be using their nuclear weapons against anyone lest they invite a far more devastating attack. The same argument, in other words, that leads Kristol and Fly to conclude we can safely attack Iran can be flipped around to conclude that we can live with and contain a nuclear-armed Iran.