I'll second Publius's devastating critique of those who advocate keeping force on the table under the theory that a credible threat of attack will somehow deter Iran. His examination of the argument's many failures is thorough and I won't repeat it here, but it is worth saying that every time we utter a threatening or hostile word towards Iran, we underscore their case for nuclear weapons. Indeed, given the possible outcomes here, we should either invade the country tomorrow morning or simply stop threatening to attack.
Every time we so much as hint at invasion, we assure an anxious regime that they won't be safe till they've mastered atomic weapons. Conversely, if we took the much-maligned route of "taking options off the table," and simply stated that we've no interest in attacking even a nuclear Iran, but we commit here and now to ten years of stringent economic sanctions if they weaponize, we'd probably have a better shot at compelling ordinary Iranians to oppose the nuclear program. But it's absolutely nuts to continually threaten a sovereign country and then scratch our heads as they pursue the one weapon they know will forever deter our attack.
