Four years earlier, however, the Canadian government had concluded an exhaustive inquiry and found that the former prisoner, Maher Arar, was telling the truth. Canada cleared Arar of all ties to terrorism and paid him $10 million in damages, and his lawyers say he's cooperating with an investigation into the role of U.S. and Syrian officials in his imprisonment and reported torture.
Arar's case illustrates what lawyers and human rights groups call a shameful trend: While U.S. courts and the Obama administration have been reluctant or unwilling to pursue the cases, countries that once backed former President George W. Bush's war on terrorism are carrying out their own investigations of the alleged U.S. torture program and the role that their governments played in it.
Judges in Great Britain, Spain, Australia, Poland and Lithuania are preparing to hear allegations that their governments helped the CIA run secret prisons on their soil or cooperated in illegal U.S. treatment of terrorism suspects. Spanish prosecutors also have filed criminal charges against six senior Bush administration officials who approved the harsh interrogation methods that detainees say were employed at U.S. military prisons in Afghanistan, Iraq, Guantanamo Bay and other sites.
Another former prisoner whose case the Supreme Court dismissed, Khaled El-Masri of Germany, has sued the government of Macedonia for handing him over to CIA agents, who he charges tortured him in Afghanistan. His case is pending in the European Court of Human Rights, in France.
The trend, although it's slow-moving and involves disparate plaintiffs, forums and legal strategies, could represent the end of a reviled chapter of the U.S.-led war on terrorism, which ensnared hundreds of detainees with the clandestine cooperation of dozens of countries. Now, some of those countries, led by new governments or under pressure from their citizens, are trying to pry open those secrets.
A spokeswoman for the Justice Department, Tracy Schmaler, didn't respond to requests for comment.
Detainees already have won one victory in a foreign court: Last November, an Italian judge convicted a CIA station chief and 22 other Americans - nearly all CIA officers and contractors - in the 2003 kidnapping of a Muslim cleric who ended up in a secret prison in Egypt. The victory was largely symbolic, however; the Americans were tried in absentia and aren't expected to serve jail time.
The Obama administration, which said it was "disappointed" with the Italian ruling, has declined to cooperate with the investigations, making it difficult for lawyers in some cases to question witnesses or gather evidence, according to experts involved in the inquiries.
In Lithuania, a criminal investigation of a former intelligence chief who allegedly helped the CIA operate secret prisons is stalled partly because U.S. officials haven't revealed the identities of detainees who were held there.
President Barack Obama's approach, from his earliest days in office, has been that "we need to look forward as opposed to looking backwards."
Although Obama outlawed the harsh interrogation techniques the Bush administration had approved, he's resisted prosecuting individuals who might have practiced them. He also opposed creating a commission to investigate the interrogation methods. His Justice Department, like Bush's, has fought to keep wrongful-imprisonment and torture cases out of court on the grounds that they would jeopardize national security, as government lawyers successfully argued in the Arar case.
Lawyers say that the Bush and Obama administrations' efforts to maintain executive power have swayed federal courts.
In the Obama administration's strongest action on torture to date, Attorney General Eric Holder said in June that a special prosecutor was close to completing a preliminary review into whether there's enough evidence to bring criminal charges against a limited number of CIA officers and contractors. The prosecutor, John Durham, was reviewing whether those individuals had exceeded the interrogation methods the Bush administration approved in fewer than a dozen cases, some of which ended in detainees' deaths.
Schmaler told McClatchy Newspapers that she had no information on when Durham's review would be made public. However, experts say the inquiry is too narrow in scope and ignores the role of senior Bush administration officials.
"It's not that we don't think they shouldn't be held accountable," Jaffer said of the interrogators. "It just seems indefensible to focus solely on the interrogators when the problems stemmed from leading officials."
The case charges that six senior Bush administration officials - including former Attorney General Alberto Gonzales, former Deputy Assistant Attorney General John Yoo and David Addington, a former chief of staff to Vice President Dick Cheney - broke international laws by promulgating harsh interrogation tactics.
A separate case is pending that involves four Spanish citizens who were held at the U.S. military prison at Guantanamo Bay, Cuba, where they say they were subjected to sexual assault, forced nakedness, death threats, severe beatings and constant interrogations without lawyers.
Judges in both cases sent letters last May asking U.S. government lawyers whether they're investigating these allegations; if they were, any U.S. cases probably would supersede the Spanish ones. To date, according to the center, the U.S. hasn't responded.
The prosecutions would mark a turnaround for Spain, which under a conservative government earlier in the decade was one of the staunchest European supporters of the Bush administration's war on terrorism.
Lithuania and Poland - where prosecutors are considering bringing war crimes charges against the country's former president and former prime minister over allegations of secret prisons - are part of what former Defense Secretary Donald H. Rumsfeld famously called the "new" Europe. It was Rumsfeld's way of distinguishing traditional powers such as France, which opposed the war on terrorism, from the continent's younger democracies, which were among Bush's early backers.
Last month, the new British prime minister, David Cameron, announced a judicial inquiry into whether British intelligence services had participated in the abuse of terrorism suspects. Cameron's decision followed a public outcry over the case of Binyam Mohamed, an Ethiopian national living in Britain who charges that British authorities knew that CIA agents were torturing him in Pakistan, Morocco, Afghanistan and Guantanamo and did nothing to stop it.
Months earlier, when the British government bowed to a court ruling and published classified details about how Mohamed was treated, U.S. intelligence officials had said that the decision was "not helpful, and we deeply regret it."
As a result, Cameron said that British courts wouldn't disclose such evidence during the inquiry and suggested that foreign witnesses - such as current and former CIA officers - won't be called to testify.
However, Siems said, the cases weren't toothless, particularly if they result in arrest warrants for U.S. officials, as they did in Italy's conviction of the CIA officers.