Torture represents a direct attack on the essence of human dignity. Its mere mention evokes a prolific and sordid history: Europe in the Middle Ages, with beds of nails, witch hunts, and burnings; the brutal methods used by military dictatorships against political dissidents in 1970s Latin America; and the gruesome photographs from Abu Ghraib, Guantanamo Bay, and other Bush-era places of detention. While leaders in the West had once hoped that...