Here's an interesting possibility of what may happen. As soon as the first US bomb lands on Iran, Iran may do something shockingly unexpected. Instead of hitting US bases in the region, they could start destroying ALL the oil facilities in the region.
Hitting US bases isn't going to cause much damage, maybe a few soldiers per missile. However, taking out 32% of world oil production would cause a crash of the world economy and the financial markets. That would cause 1,000 times more pain to the aggressor compared to killing a few soldiers. Oil prices could spike to $250-$500 per barrel and gas at US pumps would go up to $30 per gallon. That would cause massive inflation and riots and civil war.
Khamenei may give a speech saying, "My dear Muslim brothers and sisters, the Zionists and Crusaders have been killing Muslims for decades and no one did anything to save them. We have to do this for the sake of hurting the enemies of Islam. Please treat it as a sacrifice in the cause of Islamic brotherhood." Without oil, regime changes may occur in the region, which may be beneficial in the long run.