A dozen years after the terrorist attacks of Sept. 11, 2001, an independent, nonpartisan panel's examination of the interrogation and detention programs carried out in their aftermath by the Bush administration ... provides a valuable, even necessary reckoning. The work of the [11-member task force convened by the Constitution Project, a legal research and advocacy group] is informed by interviews with dozens of former American and foreign officials, as well as with former prisoners. It is the fullest independent effort so far to assess the treatment of detainees at Guantnamo Bay, in Afghanistan and Iraq, and at the C.I.A.'s secret prisons. The report's authoritative conclusion that the United States engaged in the practice of torture" is impossible to dismiss. The report found that those methods violated international legal obligations with "no firm or persuasive evidence" that they produced valuable information that could not have been obtained by other means. The task force found that using torture - like waterboarding, slamming prisoners into walls, and chaining them in uncomfortable stress position for hours - had "no justification". And in engineering "enforced disappearances" and secret detentions, the United States violated its international treaty obligations. As the panel notes, there never was before "the kind of considered and detailed discussions that occurred after 9/11 directly involving a president and his top advisers on the wisdom, propriety and legality of inflicting pain and torment on some detainees in our custody."