Late last week, two suicide bombings in southeastern Iran reduced a mosque to rubble, leaving 27 dead and nearly 300 injured. The explosions were the work of Jundollah—”Soldiers of Allah”—a rebel Sunni group opposed to the Shiite-controlled regime in Tehran. The Islamic Republic has always accused the United States of being Jundollah’s paymaster. The leader of Tehran’s government-controlled Friday Prayer even charged the U.S. with masterminding the attacks: “Since the U.S. has lost face in the case of Shahram Amiri [the Iranian nuclear scientist who allegedly spied for the U.S. against Iran] and the reputation of its intelligence has also...