“Da’esh is not protecting Muslims, it is killing them and fooling all of us,” says Khadijah, a young woman who lived in London, became disillusioned with her studies and was lured by the Islamic State (also called Da’esh) to Syria. In the end, she defected. Her story, and those of many other defectors, is now being told by the United States and its global partners. By Richard Stengel.