From the Guardian regarding US intentions toward Iran:
Vincent Cannistraro, a former CIA counter-terrorism chief who is now a security anaylist, said: “The decision to attack was made some time ago. It will be in two stages. If a smoking gun is found in terms of Iranian interference in Iraq, the US will retaliate on a tactical level, and they will strike against military targets. The second part of this is: Bush has made the decision to launch a strategic attack against Iranian nuclear facilities, although not before next year. He has been lining up some Sunni countries for tacit support for his actions.”
The president has obviously made a comittment to support Sunnis over Shias. This begs the question, why did we oust Saddam Hussein in the first place?