Maybe. But from a strictly military standpoint, wouldn't you be more worried about a country you actually share a border with and fought a bloody war with very recently? They like to use the U.S. as a boogeyman to stir up the masses but there are still lots of widows left over from the war.
No, and here's why. Iraq is no longer controlled by the Sunnis - it's majority Shia, same as Iran, and Iran's influence over Iraq is pretty complete. Furthermore, Iran has a very young population - memories of the war with Iraq have faded, and the dictator that caused the war has gone.
They see the US all around them - in Saudi, Turkey, Pakistan - and they see the results of a confrontation with the US next door. The only reason that they are not running headlong for nuclear deterrence is because against all the odds the sanctions have ground the economy into the dirt before they got the chance.