The official line out of George W Bush's White House was that torture did not happen on America's watch. In License to Torture, Panorama looks behind the Bush government's line and finds a paper trail that questions the validity of that assertion.
Previously classified papers released in Washington reveal both the path taken by the Department of Defense and intelligence agencies as they searched for interrogation techniques to employ in order to get information from al-Qaeda suspects, and the legal arguments used to validate them.
One of those techniques was water boarding, which has since been classified as torture in breach of both US and international law. Reporter Hilary Andersson finds that debate over what was - or was not - legal when it came to interrogation, has permeated mainstream America.
Declassified documents now show that both the Central Intelligence Agency (CIA) and the Department of Defense borrowed techniques from a secretive US military
training school which teaches members of the armed forces how to survive behind enemy lines and resist interrogation.
"(It) was never meant to be reversed and turned into a model for actual interrogation," Hilary Andersson says in the program. The program is partly based on techniques used by the Chinese on American captives in Korea in the 1950s.
The Department of Defense says these training techniques were never authorized, and that abuses have been fully investigated and punished. The program hears from one of the men arrested in Pakistan in 2002 and eventually taken to Guantanamo.
Omar Deghayes, a British resident and Libyan citizen who was released in December 2007, tells Panorama about his treatment at the hands of the Americans. "We were left in for one year in the cage, very small cage like an animal," he says.
"The mind starts to eat itself and you start to hear voices in your mind and you start to lose your head after, especially after a few months."
Panorama investigates who gave approvals, when and for which techniques and asks who, if anyone, should end up in the dock. Even out of office, former vice-president Dick Cheney has vigorously defended the methods used, saying they worked in that they led to key information being revealed to authorities.
For his part, President Barack Obama has said that CIA agents who used these harsh interrogation techniques will not be prosecuted. That said, he has not closed the door on the possibility of legal action against the very lawyers who approved them.