In an interview with Current TV's liberal news host Keith Olbermann, former FBI interrogator Ali Soufan -- who was pulled off terrorist interrogations by the Bush administration in the months before the CIA began torturing suspects -- claimed the attacks of Sept. 11, 2001 could have been prevented if he'd been allowed to continue his work.

Soufan's book, "The Black Banners," is available now.

This video is from Current TV's Countdown with Keith Olbermann, broadcast Tuesday, Sept. 13, 2011.