Ex-CIA lawyer Rizzo details interrogation techniques
10 January 2014 Last updated at 06:18 GMT
Former CIA lawyer John Rizzo has defended "enhanced interrogation techniques", such as water boarding, and said the US interrogation programme did not constitute torture.
Talking to Gordon Corera on Newsnight, he also said capturing and interrogating terrorists was a better method than killing people through drone strikes.
John Rizzo, who retired in 2009, was the CIA's chief legal officer. In a new book about his long career at the agency, he looks back at the agonising moral choices he often faced.