Suppose a nuclear bomb is primed to detonate somewhere in Manhattan, Levin wrote, and we've captured a terrorist who knows where the bomb is. He won't talk. By forbidding torture, you inflict death on many thousands of innocents and endless suffering on the families of those who died at a terrorist's whim — and who might have lived had government done its ugly duty.
BTW: If torture is utterly intolerable, then you MUST totally oppose war - right?