Below is the second in a two-part excerpt from The Closing of the American Border: Terrorism, Immigration, and Security Since 9/11. By Edward Alden

The Canadian government says it bears no responsibility for what happened to Benamar Benatta in a New York jail after the 9/11 terrorist attacks. The U.S. government says that its top officials — who were acting in the name of national security — are not accountable for the abuses suffered by Benatta and hundreds of other Muslim men. But who, then, is to blame for the nearly five years that Benatta, a young Algerian who had sought asylum in Canada, spent in U.S. jails charged with nothing more than a routine immigration violation?

George W. Bush came to office as the most pro-immigrant president in modern U.S. history — one who snubbed the traditional first trip to Canada because his top foreign policy priority was to negotiate a migration pact with Mexico. Yet he presided over a war on terrorism that, as liberal legal scholar David Cole puts it, “has been waged largely through anti-immigrant measures.” It began the night of 9/11, and it was Benatta’s misfortune that Canadian officials, betraying Canada’s own traditions, handed him over to the U.S. the very next morning.

Within hours of the crumbling of the twin towers, the United States had largely closed its land borders with Canada and Mexico and had shut off its airspace in an effort to seal the country against the threat of another wave of attackers from abroad. But to Bush administration officials, there seemed a graver danger: That more terrorists were already inside the country waiting to strike.

That night, Bush’s attorney-general, John Ashcroft, gathered in a secure FBI conference room all of his senior officials, including Michael Chertoff, who would later become Secretary of Homeland Security, to consider how to cut off any new terrorist plots. What they needed they did not have, which was a sophisticated intelligence network that might allow them to identify a small number of threatening individuals who could be hiding anywhere in the U.S. They began instead to discuss a much cruder approach, one that would later be dubbed the “spit on the sidewalk” strategy. As Ashcroft put it: “If a terrorism suspect committed any legal infraction at all, regardless how minor, we would apprehend and charge him.”

But who was a terrorism suspect? Just hours after the attacks, the FBI knew only one thing for certain — that all 19 of the hijackers had been young, Muslim men of Middle Eastern descent. And what was a “legal infraction?” While the idea was to use any minor violation, like spitting on the sidewalk, as a pretence for holding a suspect, in reality there was only one tool that gave the FBI the powers that Ashcroft wanted it to have — immigration law.

The FBI cannot simply arrest and hold someone indefinitely on criminal charges without a probable cause. Within 48 hours, it must bring any suspect before the courts, demonstrate lawful grounds for continued detention and allow the suspect access to a lawyer. But the safeguards are much weaker for non-citizens thought to be violating immigration laws. Ordinary due process rights that Americans take for granted — the reading of “Miranda” rights, protection from unreasonable search and seizure, the right to a government-appointed lawyer if they cannot afford one — are not required for foreigners if they are being charged only with immigration offences. As one senior government official quipped: “Immigration law is the same as tax law — you’re guilty until proven innocent.”

Before that night, immigration law had been a quasi-judicial system for determining who could stay in the country and who would be asked, and sometimes forced, to leave. As a law enforcement weapon, it had been a very small stick. But as the officials gathered around Ashcroft that night began to consider how to respond to the crisis, they realized, as one U.S. official later put it, that their existing immigration powers were “vast and underused.”

They agreed that FBI and immigration agents would fan out across the country, especially into Arab-American communities where would-be terrorists seemed most likely to be hiding. Anyone they crossed who had violated even the tiniest wrinkle in America’s vast labyrinth of immigration rules would be arrested, jailed and questioned over ties to the 9/11 attacks. But once they were off the street there was no great urgency. As Ashcroft’s deputy Larry Thompson later explained: “An individual arrested and detained posed no ongoing threat to the United States, and therefore law enforcement officials could focus on arresting others still at large who did pose a potential threat.”

There was only a single objection in the room, but it was a heated one, and it came from the man responsible for upholding the country’s immigration laws. Jim Ziglar, the commissioner of the Immigration and Naturalization Service, challenged Ashcroft. “You’re talking about doing something that’s grossly unconstitutional, when you start knocking on doors and picking up people without probable cause.”

By his own account, the exchange turned “ugly.” Ziglar held his ground but no one supported him. “What are you going to accomplish by doing this?” he argued. “You’re not going to get the information you’re looking for and you’re not going to find any evidence. And even if you did, you couldn’t use it because the courts would throw it out.”

While such arguments would eventually look prescient, they had no impact that night. Ashcroft was determined to act aggressively to head off further attacks and immigration law gave him greater powers than anything else in his arsenal. The objections of his own top immigration official were merely a nuisance. Ziglar was ordered immediately to reassign 1,000 INS agents to the mission.

“Let the terrorists among us be warned,” Ashcroft later announced. “If you overstay your visa — even by one day — we will arrest you.”

The next evening, one of those INS agents took custody of Benamar Benatta. Benatta had an unfortunate resume. A lieutenant in the Algerian Air Force and an expert in avionics, he had come to the U.S. in December, 2000 to attend training seminars at Northrop Grumman, the defence contractor. Benatta says he had fought with his military superiors over his refusal to participate in counterterrorism missions inside Algeria, which he believed were mostly aimed at innocent civilians. He had bribed his way on the trip to the U.S., intending to stay in the country. At four in the morning on the last day of the training program in April of 2001, he stole away from his hotel in Baltimore and caught a bus to New York City.

For the next six months, he lived like so many of the nearly 12 million illegal immigrants in the U.S., working a variety of odd jobs to pay for rent and food. But fearing that he would be caught for overstaying his visa, he decided to leave for Canada; on Sept. 5, 2001, he arrived at the Canadian border at Niagara Falls and asked for political asylum, saying that he would be tortured or killed for deserting the military if he were forced to return to Algeria.

Benatta had hoped to find sympathy in Canada, which had long been more welcoming than the U.S. to most political refugees. Instead, he was held in custody for a week after admitting to the Canadian border inspector that he had presented false identification, a phoney U.S. Social Security card. On Sept. 12, knowing nothing of the attacks that had taken place the previous day, he was put in the back of a car by Canadian authorities, driven across the Rainbow Bridge and handed over to a U.S. immigration agent.

Four days later, he was handcuffed, chained and flown back to New York City, where was placed on a “high security” floor in Brooklyn’s Metropolitan Detention Centre.

The story he tells of what happened next has been backed up by similar testimony from many others detained in the jail, and by an in-depth investigation by the Justice Department’s inspector-general. Benatta was held in isolation for seven months in a tiny prison cell on the ninth floor, under two bright lights that burned 24 hours a day. If he fell asleep, the prison guards would bang on the cell door to wake him.

He was subject to strip searches two or three times each day, and when he was removed from his cell the guards would twist his arms and beat his head against the wall.

In the winter the cell was air-conditioned to near freezing, and on several occasions he was chained outside in the cold for two or three hours without a coat. In the summer, the cell was heated to sweltering temperatures. A United Nations working group that investigated concluded that his treatment “could be described as torture.”

In November, 2001, FBI investigators cleared Benatta of any connection to the 9/11 attacks. Yet he would remain in the Brooklyn jail, with no access to a lawyer, for another five months until he was suddenly transferred back to a prison in Buffalo, and charged with a criminal offence for his phoney Social Security card.

The judge in the case threw the charges out, calling Benatta’s treatment a “sham” and the “height of legal folly.” He accused the government of “abandoning our constitutional principles and rule of law by adopting an ‘end justifies the means’ philosophy.”

Despite this reprimand, the U.S. did not release him. Instead, he remained in jail for violating his visa while the government considered, and then rejected, his request for political asylum. In an effort to fight deportation to Algeria, he appealed the decision, which only prolonged his incarceration.

Finally, on July 20, 2006, after pressure from the Canadian Council of Refugees, Ottawa agreed to allow him to return to Canada and make another refugee claim, which was finally granted earlier this year. At age 34, and now living in Toronto, he carries the weariness of a man twice his age, and is haunted by nightmares and depression diagnosed as post-traumatic stress syndrome. “We are not talking about five years,” he told me. “They ruined my whole life.”

Benatta has sued the Canadian government for redress, but in a statement of defence in November 2008 Ottawa said that all responsibility for his mistreatment rested with the Americans. Efforts to hold the U.S. government to account have been no more effective. Javid Iqbal, a young Pakistani who, like Benatta, was brutalized in the Brooklyn jail before he was deported, has fought a case against Ashcroft and FBI director Bob Mueller all the way to the Supreme Court, charging that their actions after 9/11 were directly responsible for the abuse he suffered. But in a hearing last month, the court appeared to set to throw out the case on the grounds that government officials should enjoy immunity for decisions taken in a national security crisis.

“The question here,” Iqbal’s lawyer asked the nine U.S. justices,” is who is responsible?” The answer, it appears, is nobody.

Edward Alden is a senior fellow at the Council on Foreign Relations, and the former Toronto and Washington bureau chief for the Financial Times. He is the author of The Closing of the American Border: Terrorism, Immigration and Security Since 9/11, from which this article is adapted.