Citation From the January 3, 2020 edition of Fox News' Hannity:

SEAN HANNITY (HOST): The president proved something with the caliphate in Syria when he wiped them out. He took off the rules of engagement of Obama and bomb the living hell out of them. Can that be done with Iran?

LINDSEY GRAHAM: Well what you can do is you can hit them where they're the weakest. What would destroy the Iranian economy is to take them out of the oil business. Here is why it is important to let Iran know what will come their way if they continue to come after Americans. I think the target list that the president is looking at if they continue to escalate is inside of Iran itself. I want them the Ayatollah to know that if you continue to come after Americans, everything is on the table including your oil refineries. I’m not speaking for the president but I do believe the target list includes targets inside of Iran. The cost of killing an American has gone up exponentially after killing Soleimani. We are safer today and if I were an Iraqi, I would choose America over the Ayatollah. We are a much better friend and a much better bet.

HANNITY: I would imagine that those refineries and maybe even those nuclear sites that are buried deep underground could be potential targets.