Earlier this month, Secretary of Defense Leon Panetta complicated U.S.-Israeli relations by calling the potential consequences of an Israeli attack on Iran’s nuclear facilities “a confrontation and a conflict that we would regret.” The remark resulted in a formal diplomatic protest lodged by Israel’s ambassador to the U.S. The Obama administration has since assured the Israelis of the existence of so-called “red lines” – in essence, the White House acknowledges that certain actions undertaken by Iran could trigger U.S. military action against it. Matthew Kroenig, Stanton nuclear security fellow at the Council on Foreign Relations and former special advisor to the Office of the Secretary of Defense, discusses the possibility of military action again Iran.