An FBI interrogator named Ali Soufan, who was involved back in 2002 goes public and blows the lid off of the Republican talking points about torture:

One of the most striking parts of the memos is the false premises on which they are based. The first, dated August 2002, grants authorization to use harsh interrogation techniques on a high-ranking terrorist, Abu Zubaydah, on the grounds that previous methods hadn’t been working. The next three memos cite the successes of those methods as a justification for their continued use. It is inaccurate, however, to say that Abu Zubaydah had been uncooperative. Along with another F.B.I. agent, and with several C.I.A. officers present, I questioned him from March to June 2002, before the harsh techniques were introduced later in August. Under traditional interrogation methods, he provided us with important actionable intelligence.

--

There was no actionable intelligence gained from using enhanced interrogation techniques on Abu Zubaydah that wasn’t, or couldn’t have been, gained from regular tactics. In addition, I saw that using these alternative methods on other terrorists backfired on more than a few occasions — all of which are still classified. The short sightedness behind the use of these techniques ignored the unreliability of the methods, the nature of the threat, the mentality and modus operandi of the terrorists, and due process.

--

One of the worst consequences of the use of these harsh techniques was that it reintroduced the so-called Chinese wall between the C.I.A. and F.B.I., similar to the communications obstacles that prevented us from working together to stop the 9/11 attacks. Because the bureau would not employ these problematic techniques, our agents who knew the most about the terrorists could have no part in the investigation. An F.B.I. colleague of mine who knew more about Khalid Shaikh Mohammed than anyone in the government was not allowed to speak to him.