In April 2004, Secretary of State Colin Powell strode into the office of his chief of staff, Colonel Lawrence Wilkerson. Some photographs were about to be released that showed American soldiers abusing Iraqi detainees, Powell said. "How bad are these photographs going to be?" Wilkerson asked. "They're going to be terrible," his boss replied. And, indeed, when the images appeared later that year, the world was shocked by what it saw: detainees being beaten, humiliated, piled up in human pyramids at Abu Ghraib prison.

Powell wanted answers. What had happened, and why? He asked his chief of staff to investigate and come up with a chronology, a "tick-tock" of the horrors. Wilkerson got to work and soon found that the abuses were not one-offs, but part of a much broader pattern. After 9/11, the military and CIA had been given full White House approval to torture terror suspects. Soldiers were abusing prisoners everywhere, Wilkerson learned, in Iraq, Afghanistan and at Guantanamo Bay. At the same time, CIA operatives were kidnapping individuals and flying them to secret dungeons around the world for "enhanced interrogation." In short, the government had launched a global torture program.

Now 70, Wilkerson shows none of his age as he darts across the hotel lobby to meet me. We hurry to a nearby bar, where he jests energetically with the doorman outside. Barely have we taken our seats before he starts talking about his vacation in London. He visits Britain regularly with his wife, he says, who loves the theatre. Shakespeare is a big favorite, especially the history plays which Wilkerson quotes verbatim as we wait for our coffee. He speaks in a warm Southern accent, often laughing but occasionally narrowing his eyes to convey seriousness.

A longstanding critic of the Bush administration's approach to counter-terrorism, Wilkerson's public pronouncements have always courted controversy. He reveals that in 2005 his home was raided by the FBI and his phones tapped after he told a panel that war crimes had been committed by senior administration officials including the vice president. He has never pulled any punches, however, and "may yet" face further persecution, he says.

Richard Armitage, then deputy secretary of state, Wilkerson and Colin Powell (L-R) during their time at the State Department under George W. Bush. Image via Lawrence Wilkerson

Wilkerson was born in South Carolina but studied in Pennsylvania. He volunteered to fight in Vietnam and, in the late 60s, saw intense combat as a helicopter pilot. Back in the US, he taught at the Naval War College before returning abroad to serve at US Pacific Command in Hawaii. Glowing recommendations earned him an interview with General Colin Powell, then Ronald Reagan's national security advisor, who was leaving the White House. Wilkerson was happy teaching and did not want the job, but Powell appointed him all the same. He would stay by the general's side for most of the next fifteen years, serving as his chief of staff when he became George W. Bush's secretary of state. Wilkerson is clearly devoted to Powell, who he refers to as "The Secretary" and describes as "the most honorable" person he has ever known in high-levels of power.

However, Powell's impressive career came to a sorry end thanks to the Iraq War in 2003. In February of that year he delivered a famous speech at the United Nations making the case for war. Wilkerson helped prepare the presentation, spending hours at CIA headquarters compiling intelligence. Much of this evidence turned out to be false and Wilkerson considered resigning in disgust, going so far as to draft a resignation letter. But he stuck it out, only to be given the Abu Ghraib assignment a year later. "I'm not feeling too good," he chuckles as he recalls the period. "Every day I'm pulling out my middle drawer and looking at my resignation letter." Eventually he concluded he could no longer serve in the Bush administration, but before he could jump, Powell was pushed, losing his job in 2005.

Wilkerson followed him into the civilian world, taking up two teaching posts at George Washington University and the College of William & Mary, where he still works today as a professor. His indignation at the Bush policies finally boiled over and he decided to speak out vocally against Vice President Dick Cheney, in particular, who he felt had seized control of the government. Sadness and anger at his and Powell's personal involvement also motivated his rebellion, he admits. "I did loathe the fact that Powell had been caught up in such an administration, and myself as well. What fired me up, however, was what I discovered regarding torture and its being authorized at the highest levels. That, and Cheney's usurpation of presidential power. And, as I did more and more research, the lies."

As a professor, Wilkerson has explored the extent of the CIA's torture program with his students, keeping up with his sources inside the intelligence community. Given the extent of his research both in and out of government, he was not particularly shocked by the Senate Intelligence Committee's report on the CIA's rendition, detention and interrogation practices since 9/11, the executive summary of which was released in redacted form last month. However, he did learn some gruesome new details — that the agency had rectally fed at least five detainees, for example.

The report does not address how the CIA program actually started. Was it ordered by the White House or did the agency decide to use torture spontaneously? According to Wilkerson, the policy came from Cheney's office. The vice president was motivated by the "awesome guilt" he felt for failing to prevent the 9/11 attacks, Wilkerson says, and had become the driving force in the administration on matters of national security. After the Twin Towers fell Cheney felt it was essential to extract intelligence from terror suspects to foil plots against the US. This would involve working on the "dark side" and using "any means at our disposal," as he explained in a famous interview on September 16, 2001.

But there was more to torture than stopping further attacks, Wilkerson insists. It also provided intelligence to justify the invasion of Iraq. The Senate Intelligence Committee's report supports Wilkerson's assertion.

So why was the former vice president so committed to torture? "Richard Bruce Cheney is an amoral hyper-nationalist," says Wilkerson. "Moreover, I believe him to be at root a man without physical courage, as testified to by his oft-quoted declaration that he had other things to do when the draft for Vietnam was operative and he was vulnerable." The brass over at the State Department — Powell, Richard Armitage (his deputy), along with Wilkerson himself — were all former soldiers, and opposed torture on the basis of their military experience. If the US abused enemy prisoners, they felt, then American captives could face torture in retaliation. Moreover, its perpetrators face the traumatic consequences of "moral injury." "Nietzsche was right," Wilkerson says. "When you look into the abyss, the abyss looks back. Or as we were taught in the armed forces, torture injures two people — the tortured one and the torturer."

Soldiers also oppose torture "for ethical reasons," he says. "When you kill for the state, that's bad enough; torture is a step too far. Of course not all soldiers believe this but it was my 31-year experience that most did. Most, for example, despised Jack Bauer on TV show 24. False bravado, we called it. And we called people like Bauer — and Cheney — cowards." Wilkerson speaks rapidly and raises his voice, clearly angry and upset by the issue. He stops to catch his breath, murmuring, "As you can tell, I'm a little passionate about it." Then he revs up again, launching into a tirade against the "War on Terror." "Look at all the innocent people we hurt and look at all the opportunity we lost and look at all the trillions of dollars we have spent and look at all the people we have killed."

For Wilkerson, the Iraq War was, and is, a strategic disaster, worse even than Vietnam. He had hoped the UK's still-delayed Chilcot Report on the Iraq war would shed some light on the fiasco, but now doubts it will be released. "I thought that Britain was doing something that we didn't have the guts to do." As he speaks a construction team is at work next door, causing the room to shudder and water to drop down from the ceiling. Wilkerson seems oblivious, even as a group of technicians bring in a stepladder and start yanking at wires up above.

He is clearly bitterly-disposed towards the CIA, which effectively torpedoed Powell's career over the Iraq War. According to the Senate's report, the CIA repeatedly misled the State Department during the rendition program, too. It concealed the existence of black sites in foreign countries and sometimes set up prisons without informing the US ambassador. Wilkerson finds this credible: "CIA often carries out actions of which the country team — including its head, the ambassador — is not aware." He did not have knowledge of any black sites while serving at the State Department and only found out about the prisons in Thailand, Poland and the Baltic States later, from government contacts. He also learned from three well-placed sources, including one veteran CIA official who personally participated in the rendition program, that the agency held prisoners on Diego Garcia, the British overseas territory leased to the US in 1966.

According to his information, the island was used as a transit site by the CIA where prisoners were detained and interrogated on a temporary basis, Wilkerson explains. He did not hear that the agency built its own, specially-designed detention facility there, like the black site in Poland recently confirmed by the country. "We didn't go there and build a prison facility and then stock it and interrogate prisoners in it, I've never heard that," he says. "What I heard was more along the lines of using it as a transit location when perhaps other places were full or other places were deemed too dangerous or insecure, or unavailable at the moment. So you might have a case where you simply go in and use a facility at Diego Garcia for a month or two weeks or whatever and you do your nefarious activities there." To build a whole new jail on the island would have been "terribly expensive", he says, because of the need to move equipment, security and construction personnel over a huge stretch of ocean.

Lawrence Wilkinson at the 25th Infantry Division base camp in Cu Chi, Vietnam in 1969. Image via Lawrence Wilkerson

Wilkerson knows Diego Garcia well from his time at US Pacific Command — long before 9/11 — and said that, because of the territory's remote location, the US often used it for secret operations. "If you wanted to do something and you wanted to do it out of the limelight, you used Diego Garcia," Wilkerson says, with a glint in his eye. "Oftentimes we would have to do things that we didn't want to get in the public eye, whether it was transferring arms to some third-world would-be coup-maker, or whatever, and Diego Garcia would be a stopover point." It would have been almost impossible for the CIA to have used Diego Garcia, even for refueling, without the British on the island knowing, he says. "I can't see how we could have used Diego Garcia for almost any function other than maybe a bounce-in and bounce-out and even that, the bounce-in and bounce-out, they'd be aware of. You can't land a helicopter there without the people on the island being aware of it."

His comments mark the first time a former Bush administration official has stated, on the record, that Britain hosted CIA prisoners on its territory. But several reports had already suggested that the CIA used Diego Garcia in its post 9/11 interrogation program and, in 2008, former British foreign secretary David Miliband admitted rendition flights had passed through the territory. There is no mention of Diego Garcia in the Senate's report — the names of the locations of CIA black sites are redacted throughout — but it was reported by Al Jazeera that the document did in fact contain references to a site there which had been established with the "full cooperation" of the British government. Moreover, it emerged recently that British government officials, including Home Secretary Theresa May, had held twenty-four meetings with Committee members to discuss redactions in the Senate report, arousing suspicions of a cover-up. Wilkerson says that "a general theme I heard was that the British were very cooperative with everything," as were "countries recently released from the Communist yoke," such as Poland. There were "rumors of suitcases full of money going to various and sundry people "in foreign governments, he says, "to keep things quiet," with huge sums going to the Poles in particular. The Senate report shows how massive bribes were paid out to allied states, including a whopping $15 million pay-off to a country widely identified as Poland.

The report portrays a rogue CIA that lies routinely to its political overseers. "Power exercised in secret is a recipe for abuse," Wilkerson says, adding that covert actions like the rendition program usually do more harm than good. Kidnapping, torture and assassination have no place in a democracy and turn the CIA into a secret police, he asserts. President Barack Obama has intensified Bush's assault on civil liberties, he believes, most notably in his expansion of mass surveillance. "It started under George W Bush, but it's just been accelerated and funded to the tune of billions of dollars by this administration." Moreover, Obama's Justice Department has gone after whistleblowers "religiously and zealously," charging more of them than all other administrations combined.

The government has a double-standard on whistleblowers, he says, punishing those who expose high-level fraud and abuse, while permitting leaks that reflect favorably on the administration. The Senate's report shows how the CIA selectively fed classified information to the press that glorified its rendition program. "You can be a whistleblower as long as you blow for the administration," Wilkerson says. The agency failed to punish incompetent officials; instead, it promoted them. "Fuck up and move up," one of Wilkerson's CIA sources told him, expressing concern about the lack of accountability.

Under Obama, the CIA continues to abuse its power with impunity. It was recently accused of hacking into the Senate Intelligence Committee's computer systems as staffers worked on the torture report. A CIA accountability board found that the CIA did not, in fact, breach the computers. Senator Dianne Feinstein disputed their findings. When Feinstein announced that her staff had been spied on in a fierce speech on the Senate floor last year, Wilkerson was so stunned that he stopped his car to listen. Later he was informed by a Senate staffer that the CIA had also physically broken into the Senate spaces to retrieve a hard-copy of the "Panetta Review," an internal CIA document that is said to back up the torture report's findings. "That's almost Watergate proportions," Wilkerson says.

He feels that Obama should have fired CIA Director John Brennan for such a blatant violation of the constitutional separation of powers, adding that fifteen or twenty years ago "I can't imagine it wouldn't have happened, but now we're in a different world." Likewise he believes that CIA and Bush administration officials should be held accountable for war crimes. But this is unlikely to happen, as Obama has already opposed most forms of accountability, from a federal truth commission, to civil litigation, to investigations in foreign countries. "We will not do something that holds the past accountable in a way that makes the future foreclosed," Wilkerson says ominously.

"The scariest thing about this administration," he says, is that they won't "close the door" on torture. Abuses of the kind documented in the Senate's report could happen again, with Britain tagging along," Wilkerson suggests. "If we had another event like 9/11, I think we'd go off the deep end. Both of us."