US is going to get bankrupt very soon. They have to fight the war in Middle East otherwise they lose the control over US dollar dominance. GCC is the heart of the US empire. They won’t be able to win this war just by air strikes or proxy or propaganda or just changing regime. Iran has a total different terrain. It’s a mountain fortress and people are hardcore Shia Muslim who believe in jihad and are willing to die for their religion. Also they are currently operating in a decentralised manner. The only option US has is to send troops to invade and if they do that, they are going to lose political support with people rioting all over the country.