As a radical Islamic army marches across Iraq, America is making a deal with the devil. Qassem Suleymani, the head of Iran’s secretive Quds Force, is allied with us in Baghdad — but he’s plotted to kill Americans elsewhere. As Kenneth R. Timmerman reveals in his new book, “Dark Forces,” Suleymani was even the shadowy figure behind the killing of Ambassador Christopher Stevens in Benghazi, Libya. He’s the Wizard of Oz of Iranian terror, the most dreaded and most effective terrorist alive. He is Qassem Suleymani, the head of the Quds Force, an organization that acts as a combination CIA...