A senior CIA official, meeting with Senate staff in a secure room of the Capitol last June, promised repeatedly that the agency did not violate or seek to violate an international treaty that bars cruel, inhumane or degrading treatment of detainees, during interrogations it conducted in the Middle East and elsewhere. But another CIA officer -- the agency's deputy inspector general, who for the previous year had been probing allegations of criminal mistreatment by the CIA and its contractors in Iraq and Afghanistan -- was startled to hear what she considered an outright falsehood, according to people familiar with her...