In 1992, the Central Intelligence Agency hired the young historian Nick Cullather to write a history (classified "secret" and for internal distribution only) of the Agency's Operation PBSUCCESS, which overthrew the lawful government of Guatemala in 1954. Given full access to the Agency's archives, he produced a vivid insider's account, intended as a training manual for covert operators, detailing how the C.I.A. chose targets, planned strategies, and...