That's the question raised in The Atlantic's September cover story, and is also the topic of my Scripps Howard column with Ben Boychuk this week. My take:
An attack on Iran, whether by Israel or the United States, would have devastating consequences for the rest of us: Iran would almost certainly respond by unleashing its terrorist proxy groups to make war on Western targets, and it could easily make life miserable for shipping in the Straits of Hormuz -- a critical passage for oil exports from the Middle East to the rest of the world. Many people would die, and a shaky world economy might be plunged into depression.
And that's what would happen if the attack worked.
Iran learned the lessons of Israel's attacks on nuclear facilities in Iraq and Syria during the last three decades. The country has spread out and buried its key nuclear facilities. Western intelligence probably doesn't know where all those facilities are located. Even proponents of an attack admit that bombing Iran might not keep that country from obtaining a nuclear bomb -- it just might slow the process a little bit.
Whether you believe an attack is justified, then, depends on your answer to this question: Are Iran's leaders so crazy they would actually use a nuclear bomb once they obtained it?
Certainly, there's little reason to love President Mahmoud Ahmadinejad, or the mullahs who back him. They are Holocaust-denying totalitarian theocrats. But there's little evidence they're ready to commit national suicide. If Israel didn't destroy Tehran with a retaliatory nuclear attack, the United States almost certainly would.
A nuclear-armed Iran is undesirable. It may also be inevitable. The suffering unleashed by an attack on the country, though, would be guaranteed -- while the consequences of a nuclear Iran remain, at this point, hypothetical. If the debacle in Iraq has taught us anything, it is that we should wait for a true threat to reveal itself, instead of squandering blood and treasure trying to ward off a chimera.
Ben's solution? "Let's kill the mullahs."