The Islamic State of Iraq and Syria (ISIS) has changed its name more often than a rock band. The Sunni extremist group that has fought in Syria and plotted attacks in Saudi Arabia and Lebanon has now upped the stakes, advancing through Iraq and declaring itself the Islamic State (IS). In Iraq and Syria, the group has slaughtered Shiites and members of other religious groups it deems apostates, as well as Sunnis perceived as collaborators with the Iraqi government. Its brutality has led to confusion about its aims and dangers. In the spirit of “know your enemy,” let’s dispense with some myths about IS.