Tom Ricks doesn't think that Israel will bomb Iran:
I just don't see how Israel could physically do it as long as the Americans are in Iraq. Hitting Iran is a tough mission to begin with for Israeli aircraft. It would probably be impossible for Israeli aircraft to hit Iran without passing through Iraqi airspace -- and they could not do that without the Americans knowing and being able to stop them. Thus the U.S. government would be seen by Iraqis and others as an accomplice of the Israeli attack. The fallout of such a bombing would make life in Iraq very difficult for more than 130,000 U.S. troops, even before the Iranians embarked upon a course of retaliation that probably would include stepping up roadside bombings of U.S. forces.