Don't forget that Iran has medium range missiles, and would be perfectly capable of doing remote damage to US land and sea forces in Iraq, Turkey and other areas in the Middle East if it decides to get defensive. It would take an incredibly successful and coordinated initial barrage from the US to remove that capability. And that's not likely to happen either.
I think it's more likely that this whole pantomime is yet another cynical move to drive up prices. Bush probably doesn't much care that it will ruin the US as long as his Texas and Saudi buddies are getting richer. He really does seem to be that stupid, disconnected and cynical.