There are 166 detainees in Guantanamo, of which up to 16 are “high-value detainees” who were sent in from CIA black sites; 86, meanwhile, have been cleared for release, and the status of the remainder is (for no good reason) classified. The vast majority of these are not hardened terrorists. Indeed, many are like Mohamedou Ould Slahi, a Mauritanian who has just published a terrifying memoir of his treatment in the facility. As long ago as 2007 it was determined there was no evidence to try him on, and yet six years later he remains in a cage there.