Guantánamo Diary is no masterpiece: inevitably, it’s repetitive (Slahi likens his interrogations to Groundhog Day), and often banal when what it recounts isn’t revolting. But Slahi is an intelligent and sensitive writer whose sense of irony somehow survived along with his sanity. He’s not quite Holden Caulfield but his personality consistently comes through. His efforts at characterisation – of his interrogators, guards and fellow detainees – are thwarted by the military censors’ redactions, which turn a wide cast of villains, friends and villain-friends into so many undifferentiated black marks. But his collective observations of his jailers – especially the prison’s racial dynamics, with white guards dominating their black colleagues, and a Puerto Rican contingent showing the most sympathy to the jailed – are some of the book’s most striking details.