Argument: Verifying effectiveness of enhanced interrogations is too difficult
Steven G. Bradbury, then the Justice Department's principal deputy assistant attorney general, wrote in a May 30, 2005, memo to CIA General Counsel John Rizzo: "It is difficult to quantify with confidence and precision the effectiveness of the program."
When asked "Have any attacks on America been disrupted thanks to intelligence obtained through what the administration still calls 'enhanced techniques?'", Bush's FBI director Mueller said in 2008: "I'm really reluctant to answer that", then "I don't believe that has been the case. [...] That's a hard call, Jay. I can believe you or I can believe the FBI director, internal CIA reports, and the interrogators that got the information you allude to. Let me think about that and get back to you..."