Further reading of the NeoCons attempts to relaunch themselves shows that they may have more in mind than getting an early start in the post-election recriminations of the Republican party. In addition to re-affirming their commitment to 'stay the course' the NeoCons want to invade Iran as well.
One of the most infuriating features of the NeoCon cabal is their attempt to claim that the future is inherently unpredictable and so there is no reason to suppose that their wishful thinking might be entirely wrong. The invasion of Iraq 'might' have been a cakewalk, but most serious analysts predicted that the occupation following the invasion would be very grim.
So now that they are planning to attack Iran seems a good time to point out the likely outcomes.
The best outcome then is that Iran simply ignores the attack and continues as if it never happened without attempting to retaliate, in other words the best outcome that can be reasonably expected is that the US position is no worse after the attack.
It is rather unlikely that Iran will not retaliate. They have three possible avenues to do this. The first is to use their proxies in Lebanon to attack Israel. Iran demonstrated its willingness to do this three months ago when it allowed its proxy Hezbollah to escalate tensions by kidnapping an Israeli soldier. The second avenue is to use their proxies in Iraq to attack the US directly. The third avenue is to go for the West's jugular and shut down transport of oil through the Straits of Hormuz.
My guess is that the Iranians would go for the second and third option. The second being not so much an option as a more or less inevitable result, if the US attacks Shi'ias in Iran the Shi'ia militias in Iraq are going to find it much easier to recruit causing the Iraqi civil war to escalate further.
Even if Iran was a fourth rank military power it would have no difficulty in blockading the gulf. Supertankers are the slowest ships imaginable, their cost is stupendous. The insurers are risk averse. Iran was only persuaded to suspend attacks on tankers during the 1987-88 tanker war because it could not afford the risk that the US would assist Iraq in the Iran-Iraq war. The cease-fire was signed months later.
Today Iran has what it did not twenty years ago - surface to sea missiles allowing it to effectively control the straits without the need for surface boats.