From Germany to Guantanamo: The Career of Prisoner No. 760

Hochfeld, a section of the western German city of Duisburg, is a classic, 20th-century working class neighborhood, a place of run-down houses two and three stories high, most of them badly in need of a fresh coat of paint. Those who were able to leave the neighborhood have moved away, replaced by a new underclass of immigrants hoping for a better life in the affluent West.

Mohamedou Ould Slahi was one of them, or at least he appeared to be. He arrived in Germany as a student from Mauritania, a thin young man with noticeably good manners. The many FBI and CIA agents who would later interrogate him in Mauritania, Jordan, Afghanistan and, finally, Guantanamo, were astonished by the incongruity between his politeness and the monstrous acts committed by al-Qaida, to which, as a result of their investigations, he was linked.

Slahi lived in a yellow, two-story building at Eigenstrasse 92. His two-room apartment was on the ground floor, on the right-hand side of the building. He married a 17-year-old girl from his native Mauritania, and she moved in with him and learned to speak German. A young, ambitious couple, they could have been model immigrants. To this day, she says that she had no idea about her husband's double life.

Slahi, now 38, is believed to have been a major player in the terrorist network assembled by terrorist leaders Osama bin Laden and Ayman al-Zawahiri to conduct militant jihad against the "infidels" and "crusaders" -- especially against the world's superpower, the United States. Slahi apparently knew several of the terrorist pilots behind the Sept. 11 attacks, who met regularly at the apartment of their ringleader, Mohammed Atta, on Hamburg's Marienstrasse. Students like Slahi, who also led double lives. One of his relatives was even higher up in the al-Qaida hierarchy.

Agents at the FBI and CIA, as well as former Defense Secretary Donald Rumsfeld, view Slahi as a central figure in international terrorism, a man partly responsible for murderous attacks on New York and Washington. Rumsfeld, who left office in 2006, was familiar with the Slahi file, and it was Rumsfeld who issued a direct order to interrogate the prisoner -- using torture, if necessary -- until he revealed what he knew. By then, Slahi was being held in Guantanamo.

Even today, the Americans believe the Mauritanian presents a considerable danger. They base their claims on highly incriminating testimony -- including that given by Ramzi Binalshibh. Binalshibh, who was also in Germany before Sept. 11, 2001, lived in Hamburg and knew at least two of the pilots involved in the attacks. Binalshibh, too, is being held at Guantanamo, and it's possible he will receive the death penalty.

It is beyond doubt that Slahi was a promoter of global jihad. He preached in gloomy backyard mosques in cities like Duisburg and Krefeld, telling Muslims from Germany's industrial Ruhr region about the consequences their faith should have for their lives. He sent money to a high-ranking member of al-Qaida, which made him suspicious. He traveled to Afghanistan, which made him even more suspicious. He moved like a fish in water in a milieu that was home to some of the world's most-wanted terrorists.

These are all clues that weigh heavily in a post-Sept. 11 world. Nevertheless, if he were brought to trial under the rules of a constitutional state, prosecutors would have great difficulty proving him guilty. But Guantanamo is a legal gray zone -- and prosecuting terrorists is significantly easier there, at least for the time being.

Slahi's case is exemplary of the years before and after Sept. 11, 2001. His life history documents, almost without interruption, a decade of terrorism against the West, as well as the West's difficulties in finding a suitable response to it. Slahi's biography is yet another example of why the Guantanamo system has failed. Thanks to a wealth of documents, letters and testimony, it can be reconstructed in greater detail than almost any other case. It also demonstrates that Germany seemed practically ideal as a haven for jihadists, at a time when most Germans had never even heard of the name Osama bin Laden.

A man who remains unshakably loyal to Slahi is his younger brother Jahdih, who lives in Düsseldorf today. His studio apartment has become a center of operations for the Mauritanian's supporters. Jahdih followed his brother, and role model, to Germany at a time when Mohamedou was already back in Mauritania, where he disappeared in 2001. In fact, Mohamedou paid for his brother's ticket to Germany.

In October 2002, Jahdih Ould Slahi finally discovered where his brother was -- in Guantanamo -- through an article in SPIEGEL. Today, Slahi writes letters to his younger brother, sometimes in German, containing advice: "I know that you like computer hardware, but try learning a programming language like Java; that sort of thing is in demand in Germany."

Such passages can also be interpreted in another way: Choose your own path, but don't follow in my footsteps.

Mohamedou Ould Slahi gave his brother Jahdih power of attorney to handle his affairs, including the coordination of his legal defense. In the letters he wrote to the president of the United States, to the former defense secretary and to Secretary of State Condoleezza Rice, Jahdih insisted that his older brother was innocent.

A Son in Guantanamo

At noon on a Friday in June 2008, the Slahi family convenes at the offices of the International Red Cross (IRC)in the Mauritanian capital Nouakchott. His mother, brothers, sisters, nephews, nieces and aunts are all dressed in the flowing robes they would normally wear to a family party. They have come here to talk to Mohamedou, their lost son, by telephone. The Joint Task Force in Guantanamo has granted its approval, with the IRC acting as go-between. Thick carpets cover the stone floor and light-colored curtains billow at the windows of the IRC office.

"My son, my son, how are you feeling?" his mother asks. "I am so happy to hear you." She breaks into tears, as she hears his voice for the first time in more than six years. Mohamedou's older brother speaks with him for 40 minutes. Slahi tells his brother that he is doing well. He wants to know who has married whom, how his siblings are doing and who has had children. "That was my brother, the brother I know. He has not changed," Hamoud Ould Slahi says after the conversation.

This summer marked Slahi's sixth year in Guantanamo. The once-intractable detainee, physically delicate but iron-willed -- who cursed his interrogators and complained about being "treated completely unfairly," as an official with Germany's foreign intelligence service, the BND, noted -- has turned into a model prisoner. This is why he enjoys privileges, including the telephone conversation with his family. The interrogators refer to his cell as a "suite," because it is larger than other cells and contains a computer and a color TV. Slahi is permitted to order food from McDonald's and shares a small tomato garden with other prisoners.

His interrogators consider the Mauritanian to be one of their best sources. He has prepared Excel tables and figures to explain the inner workings of al-Qaida to them. He has even written an autobiography in his "suite." "Slahi is a short, tiny little guy. He's got no beard, and a child-like face," one of the men who regularly interrogated him told SPIEGEL. "He is an extremely intelligent, very pleasant person and an excellent chess player."

But how did he then get to Guantanamo? And where did his career begin?