In 2003, the Macedonian police arrested Khaled el-Masri, a German citizen vacationing in their country. They handed the unfortunate man over to the CIA, who shipped him off to one of their “black sites.” For those too young to remember (or who have quite understandably chosen to forget), “black sites” was the name given to clandestine CIA detention centers around the world, where that agency held incommunicado and tortured men captured in what was then known as the Global War on Terror. The black site in this case was the notorious Salt Pit in Afghanistan. There el-Masri was, among other...