Joint Chiefs of Staff Chariman Adm. Mullen said today that the United States has a plan of attack for Iran in order to prevent it from acquiring nuclear weapons.
Such a declaration is an incredibly important (and unsubtle) part of a US intimidation/containment strategy with Iran in order to prevent such an acquisition from happening.
By announcing these plans, the US is publicly showing that, despite its draining presence in Afghanistan, it is willing to commit to striking Iran's nuclear infrastructure and dealing with the painful consequences. In short, it made it clear that a nuclear Iran is a worse scenario than a war with Iran.
With that clarity, of course, Tehran must try to guess whether the US is bluffing, or if it's serious. If it's serious, Tehran must seriously begin re-thinking its decision to pursue nuclear weapons.
The US air force and navy are minimally committed in Afghanistan, and have bases all around Iran (and can invade the Persian Gulf very easily). Iran's anti-air infrastructure would probably quickly crumble, allowing the US air forces to move with relative ease throughout Iran, and blockade the country from oil experts.
The most negative consequences for the US would likely be unconventional:
-The Chinese and Russians have strong economic/oil ties to Iran, and would protest furiously, if for no other reason than to make sure the oil keeps coming.
-Iran has a lot of power over Hezbollah, Hamas, and groups in Iraq and Afghanistan. No doubt, it could make life very difficult for the United States.
-There is some risk of alienating the anti-Iranian coalition, but odds are good that Saudi Arabia, Egypt, and Turkey would be, generally, in support of such action. Jordan and Syria would be the toss-ups.
-The Revolutionary Guard could actually be highly disruptive in Iraq, although if the US is able to bomb out roads heading towards Iraq, it could mitigate such issues.
Attacking Iran would be seriously costly in a number of ways, but if the US is actually committed to it (it likely is--the US has never been caught bluffing since the Bay of Pigs and the anti-Soviet Hungarian Revolution).
This could be a game-changer in the Iranian nuclear contest.