In a hearing Carl Levin, the Democratic head of the Senate Armed Services Committee, tied US interrogation policies - which critics say have included torture - to Donald Rumsfeld, the powerful defense secretary from 2001 to 2006, and other top officials in President George W. Bush's administration.
Counter to the Bush administration's argument that mistreatment at the prisons arose from simply a handful of out-of-control military jailers, or a "few bad apples," Levin said a high-level debate raged in the US defense and intelligence community from mid-2002 over techniques such as waterboarding, menacing dogs and sensory deprivation.
Citing previously secret documents and testimony from those involved, Levin said that in the internal government debate, US armed services lawyers raised strong doubts over whether the techniques were legal or useful.
But, Levin said, a Central Intelligence Agency lawyer who met with Guantanamo staff on October 2, 2002 argued that torture "is basically subject to perception."
"If the detainee dies, you're doing it wrong," Jonathan Fredman, then chief counsel to the CIA's Counterterrorism Center, told the meeting, Levin said.
Two months later, after the Guantanamo detention camp's senior legal officer Lt.-Col. Diane Beaver wrote said they would "need documentation to protect us" from potential legal charges over alleged torture, Rumsfeld signed a letter authorising most of the interrogation techniques recommended, Levin said.
Rumsfeld added to the December 2nd, 2002 letter, Levin said, a written comment on one technique that "I stand for eight to 10 hours a day. Why is standing limited to four hours?"
"How on earth did we get to the point where a senior US government lawyer would say that whether or not an interrogation technique is torture is, quote, 'subject to perception,' and that if, quote, 'the detainee dies, you're doing it wrong'?" Levin asked.
"Were these actions the result of a, quote, 'few bad apples,' acting on their own? It would be a lot easier to accept if it were, but that's not the case," he said.
"When Secretary Rumsfeld approved the use of abusive techniques against detainees, he unleashed a virus which ultimately infected interrogation operations conducted by the US military in Afghanistan and Iraq," he said.
According to Alberto Mora, former general counsel for the navy, there was strong resistance to the interrogation techniques, within Pentagon legal circles and from US allies.
He said that a memorandum from Beaver providing legal arguments for use of a broad set of rough interrogation techniques along with Rumsfeld's letter were "completely unbounded concerning the limit of abuse that could be applied to the detainees."
"I knew instantaneously, sir, that this was a flawed policy decision based upon inadequate legal analysis," he told during Tuesday's hearing.
Asked if other senior Pentagon lawyers shared his view, Mora replied: "Sir, every judge advocate I've ever spoken to on this issue shares that view."
Mora also testified that he understood that US allies hesitated to join in combat operations, and declined to participate with US forces in detainee handling training because of concerns over US abuse of detainees.
"Senior NATO officers in Afghanistan are reported to have left the room when issues of detainee treatment were raised by US officials out of fear that they could become complicit in any abuse," Mora added.