Senator Graham doubts success of U.S.-Iran deal, while Trump threatens retaliation if Iran continues attacks on Israel via Hezbollah.

GOP Sen. Lindsey Graham of South Carolina said he expects a diplomatic solution with Iran to fail, though he noted that he would "rather try diplomacy than take it off the table."

Senator Graham doubts success of U.S.-Iran deal, while Trump threatens retaliation if Iran continues attacks on Israel via Hezbollah.