Atta in Hamburg

Mohammed Atta cultivated an academic life, German friends and a terrorist network. How did this sterile city become the launch pad for 9/11?
September 19, 2002

Hamburg used to be known for such trivial charms as the Reeperbahn red-light district, and as the place where the Beatles had their first international success. It has long enjoyed the reputation of being a tolerant, prosperous, almost Scandinavian port city in Germany's placid north, with a strong social democratic tradition and the half-justified conceit that Hitler never made it there. It is a city you neither love nor hate: you just take for granted its comforts and complain about its permanent cloak of cloud and rain. For me, Hamburg was the pleasant but sterile city where I spent my high school years, and which I couldn't wait to leave for less well-organised, more passionate places. I did. Yet, over the years, I developed an affection for Hamburg's understated civic pride. So it was a shock to discover, shortly after 11th September, that it was Hamburg that had served as the secret launch pad for the most devastating terrorist attacks in modern history.

Three of the four suicide pilots (Mohammed Atta, 33, Marwan al-Shehhi, 23, and Ziad Jarrah, 26) and many other supporters had spent many years in Hamburg as foreign students. It is not clear whether they arrived in Hamburg as sleepers or whether they were recruited while living there. In any case, Hamburg emerged in the 1990s as an al Qaeda centre second only to Afghanistan. Why Hamburg? Is it something about the city's tidy anonymity, its openness to foreign students, that made it a chosen centre?

Ziad Jarrah rented a room around the corner from where I grew up, in an elegant Jugendstil building on the leafy street I walked along to school. Atta was based in the less familiar Harburg, an industrial suburb south of Hamburg. He began his studies there in 1992, at the local Technical University Hamburg Harburg (TUHH). His flatmates, Ramzi Binalshibh, Said Bahaji and Zakhariya Essabar are all implicated in 11th September-investigators believe that Binalshibh's role was to recruit new al Qaeda members.

Every other house in the treeless, eerily quiet narrow streets of Harburg carries an unassuming stone plaque. Destroyed 1944. Rebuilt 1956. Destroyed 1943. Rebuilt 1954. These inscriptions, darkened by five decades of rough Hamburg weather, celebrate the rebirth of a city crushed by allied bombing.

Marienstrasse 54 is a faceless, unadorned 1950s four-storey building squeezed into a straight row of its clones. It has a yellowish facade, small PVC-framed windows; clean and tidy except for a lone uneven graffiti-"suck." There is no plaque, unless you count this invisible one: Mohammed Atta lived here, 1998-2000. I wonder whether, when he walked these streets, he ever thought about their history. I doubt it. The man who was perhaps the ringleader amongst the 19 hijackers had a different sense of time and history, rooted in an idiosyncratic reading of events that occurred in seventh-century Arabia. This past is infinitely more vivid to him than the second world war. In fact, it is hardly a past at all: it is a model for what he hopes, through his martyrdom, to recreate in the present. When he walks past a pub called Las Vegas, he does not yet know that he will soon visit the real Las Vegas. When he shops at the supermarket next to his nearest S-Bahn stop, he looks away, disapprovingly, from the alcohol by the checkout counter. When he stocks up on sweets-he has a very sweet tooth-he scans the packages carefully, looking for animal ingredients. He is a devout young man.

Mohammed Atta, the man with three passports, was known in Hamburg as Mohammed El-Amir, a short version of his full Egyptian name, Mohammed El-Amir Awad el Sayid Atta. Of all the names and photographs associated with 11th September, Atta's square, clean-shaven face with a helmet-like crop, hard lips and a squint in the left eye, instantly became the most prominent. Posthumously, he grew into a sinister media darling. Here in Marienstrasse, minutes away from the university, he lived quite simply as a diligent student of city planning.

The windows of what used to be his Harburg flat (called Beit-al-Ansar, the house of supporters) are now conspicuous by being the only curtainless ones in the building. The flat on the first floor is empty, the name tag gone. Neighbours are, by now (this is a few months after the attacks) unwilling to talk. One says, with a smile: "I know why you are here, and all I can tell you is that there were many of them. Too many to remember an individual face." Nearby shopkeepers say they don't recall "those guys." I don't know whether this is the truth, but I do know that it is possible to live in a Hamburg neighbourhood for years without befriending, or even recognising, a single soul. If you pay your rent on time and don't cause any trouble, you can become invisible.

Still, I try my luck one more time. A few yards down the street is a traditional shoemaker's shop. In the window is a display of old-fashioned German sayings praising hard work and frugality. I walk in, glad to escape the rain. The shop is empty, and silent, for a while. I wait. It smells of leather and shoe polish. There is a shelf of shoes for sale, ladies and gents, unfashionable in a timeless sort of way. Suddenly, Herr R appears; he is in his 60s, a tall, confident man, with an air of authority. I explain my presence expecting to be told that he remembers nothing about the inhabitants of Marienstrasse 54-but he does.

"Yes, they came here a few times. Of course I remember them. They were foreigners; one recognises foreigners. This neighbourhood is not what it used to be. Lots of foreigners. Sometimes, they come and tell me I should convert to Islam."

He seems to be talking about a whole group, but then makes it clear he does not mean the ones whose pictures were in all the papers and on television.

"Not them. They were very proper. Polite. Spoke excellent German."

"What sort of shoes did they wear? Trainers?"

"Oh no." He picks up a pair of sombre, shiny black shoes with laces: "Something like this. Classic, elegant. Expensive."

I ask him what state those shoes were in, what did they ask him to repair? A shoemaker can tell a few things from the condition of one's shoes.

"The usual. Heels, mostly." He pauses. "I refused to do those on the spot, said I'd do it overnight. He wasn't pleased and took them away. "

"Why didn't you fix the heels while he was waiting? You have a sign in the window that says you do."

"Yes," he smiles, "but... I could see he had done something to those heels himself, tampered with them, cut them off, glued them back, and it looked awful. He wanted me to make it look professional again, like they hadn't been touched. But he wouldn't leave them with me... I knew there was something odd about those Arab students."

Do many students live here? "Not many. But many foreigners. The rents are cheap. They didn't have a phone. Made calls from a phone booth. Neighbours offered them the use of their phone, but they refused." According to the landlord, Marienstrasse 54 did have a phone, in addition to a number of high-speed internet lines set up by the tenants themselves. Presumably, some calls were made from outside to reduce the risk of being tapped.

Were the men, or man he is talking about, friendly? "No. Arrogant. I didn't like him." This is a deviation from all the other German opinions I hear about Atta and his friends. In Germany, everyone else found Atta "nice." But in America his flight instructor and landlord also described him as arrogant.

Does my conversation with the shoemaker qualify as "finding a trace"? It feels like it, even though no names were mentioned. As I walk out into the rain, I think of the first trace of Atta I did find. A Google internet search came up with a French website, Bab Souria (Gate of Syria), where he registered on 5th December 1997 under the name Mohammed El-Amir, giving his location as Hamburg. In English, he had typed: "I'm an Egyptian architect. Now I'm studying urban planning in Germany. I'm preparing my graduation project about the old city of Aleppo." (It argued for the need to resist corrupting western elements in Muslim architecture.)

On the website, he asked for any interesting information about Aleppo. For some reason he lied, claiming that he had no e-mail address. He had at least one: el-amir@tu-harburg.de. The university provided him, like all its students, with an e-mail account. In 1999, it also gave Atta and his fellow Muslim students a room to pray in. It was called Islam AG (Arbeitsgemeinschaft, work group) and, aside from a praying carpet, it was equipped with a computer. An anonymous member of the university student organisation posted this witness account on the internet: "I was at the January 1999 meeting at which the founding of Islam AG was first discussed. I can confirm that, although Mohammed El-Amir Atta was strongly religious, he appeared quite normal. At the meeting, I was critical of the idea of an Islam AG, being of the opinion that universities should be religion-free and that our student organisation should not promote any sort of religious proselytising. During the discussion it became clear that this would not be the case. The main concern was to have a place to pray. One has to consider cultural differences. A Muslim prays five times a day. If he has to run to a mosque each time, normal study becomes impossible. The praying room is supposed to take into account these cultural differences, to allow Muslim students a regular university routine. Atta was strongly religious, but did not appear fanatical, and it was also not noticeable that the praying room had ever been used for any conspiratorial meeting."

This choice of words seems to reflect Atta's ability to be gently persuasive, without attracting undue attention. He got his way by appealing to the German students' need to be fair to members of other ethnic and religious groups. Soon, Islam AG began attracting Muslims from outside the university, organising well-attended lectures on Islamic themes.

What do we know about Atta's life before he arrived in Hamburg from Cairo in 1992, at the age of 24? He was born in 1968 in the Egyptian village Kafr el-Sheikh, north of Cairo, in a rural corner of the north-central Delta. He grew up in Cairo, at a time of a huge influx from the countryside. Between 1930 and 1950, Cairo's population doubled to 2m; by 1980 it had 8m inhabitants. It is now the most densely populated city in the world. Atta senior was one of many who became upwardly mobile on the wings of the 1952 revolution via the army, police and bureaucracy. Until the revolution, Cairo had been, for the most part, a liberal, cosmopolitan city which, in addition to a traditionally religious but seldom militant Muslim population, accommodated Christians and Jews. In the 1940s, Cairo's spirit infected other Arab cities like Beirut and Baghdad, attracting talent from everywhere in the Arab world. The tensions between secularists (trade unionists, communists and other groups modelled on European ideals, including fascism) and traditionalists (from the radical Muslim Brotherhood to moderate defenders of Islam) had been brewing for decades.

The end of the second world war had brought an end to British colonialism, but King Farouk did nothing to end the hunger and poverty. The defeat in 1948 by the young Jewish state was a humiliating blow. The king was overthrown in 1952 and in 1954, the charismatic officer Gamal Abd al-Nasser took charge of the revolution and introduced a Soviet-style government. Everything was confiscated-from the Suez Canal to bank accounts with more than £10,000. By 1955, thousands of dissenters had been sent to prison and the Muslim Brotherhood was smashed. Nasser also introduced a new cityscape to the capital: concrete towers became symbols of the post-colonial age, based on Arab unity and state socialism. Young Saddam Hussein, who had fled to Cairo in 1962 after shooting an Iraqi politician, studied law there and soaked in the spirit of Nasserism.

By the end of the 1960s, when Atta was born, Nasser had been defeated in another war with Israel in which 12,000 Egyptians had been killed. In 1970, Nasser died and was replaced by his associate, Anwar al-Sadat. Quickly shedding the Nasserite mask he had worn for years, Sadat kicked out Soviet advisers, invited capitalist investment, replaced Arabism with Egyptian nationalism, freed prisoners and talked about elections. In the 1973 war with Israel, Sadat recaptured a part of previously lost Egyptian territory, gaining the rest back in a peace treaty with Israel, which he signed separately from his Arab allies.

The Cairo of Atta's childhood was a demobilised city, newly reopened to private investment, foreign aid and tourism. The city rediscovered its nightlife and a western-style consumerism. But it was also a city, and a country, that was not coping with its population's basic needs. According to polls, the majority of graduates were hoping to emigrate. In October 1981, Sadat was assassinated by Islamic Jihad activists disguised as his own soldiers.

One of the hundreds of those arrested in the aftermath of the assassination was Ayman al-Zawahiri. (His Islamic Jihad group merged with al Qaeda in the late 1990s and he became, and remains, Osama bin Laden's second in command.) Al-Zawahiri was indicted for possession of weapons and sentenced to three years in prison. He left Egypt two years after his release, first for Saudi Arabia, then Pakistan, joining forces with the Islamic militants arriving in Afghanistan to fight the Soviet Union. Nasser had imprisoned and tortured Islamic militants; Sadat had released and even quietly supported them, as protection against the left he feared more. But the freed militants wanted to destroy Egypt's government. Sadat's follower, Hosni Mubarak, cracked down again on the militants and the struggle in Egypt between government and radical Islam continues to this day. The only difference is that it has now spread to the rest of the world -thanks in part to Zawahiri. In one of bin Laden's videos, he referred to "Mohammed of the Egyptian family"-probably a reference to Atta and his membership of a Zawahiri-led Egyptian cell. According to sources, the Egyptian secret service had been warning the Americans about Atta for some time.

Max Rodenbeck describes the Cairo of the mid- to-late 1980s as a "megacity, complete with international chain stores, high-tech discos, theme restaurants... television-aired Hollywood serials." But jobs, housing and decent wages were scarce; "even sex was effectively denied many, since Egypt's strict conventions demanded marriage, and marriage required money for dowries and furnishings and apartments." Many marriageable Cairenes remained single-suggesting widespread sexual frustration.

Atta, a lawyer's only son, felt the burden of the family's middle-class ambition, and his own. A school friend described him as "a shy boy who had always wanted to become a civil engineer." His father had wanted him to "toughen up" and to succeed. He pushed him to take foreign language classes-English at the American University, German at the Goethe Institute: expensive propositions. Later, it was the father who made the boy go abroad to study. Atta had never wanted to leave Egypt.

Yet, in Cairo, he belonged to a generation which, according to Rodenbeck, "felt betrayed by the slogans of the past-by shrill nationalism and half-baked socialism. Looking for a source of hope, Cairo's youth found a simple message plastered all over the city. The message was, 'Islam is the Solution.'"

After six semesters of architecture studies at Cairo university, and some jobbing as a foreman at construction sites, Atta left for Hamburg. He left behind a city and a university undergoing a big return to Islamic values. He would arrive in secular, free-spirited Hamburg, an alien city and culture where loneliness is a familiar feature of daily life, not only for foreigners. In Islam, he would seek and find human warmth, a connection with home and like-minded people, perhaps a cure for the depression of an immigrant without a family. At some point, it would also suffuse his life with a sense of mission.

Today, Atta senior receives journalists in his apartment in a middle-class neighbourhood of Giza. He is a man with a grudge. In interviews with foreign journalists-to whom he serves alcohol-free beer-he rants about America, without answering or listening to questions. He accuses the Mossad of being responsible for 11th September, and of framing his son, from whom he claims to have received a phone call, "checking in," 24 and 48 hours after the attacks. To another journalist, he says that in all the years since his son left home to study in Germany, "we never had his phone number. He called us regularly, but we couldn't call him." Atta's mother is separated from the father. He has two older sisters, both successful women with PhDs; one is married.

German television researchers have obtained and shown a few photographs of Atta as a young man. In one, he looks no older than 14: a curly-haired boy, enduring his pretty mother's loving embrace with the uneasy smile of a typical adolescent. In another, he is shown with his fellow Cairo University students; he looks comfortable here, at ease.

At Cairo University, Atta's faculty was a hotbed of fundamentalism and the Engineers Syndicate he joined in 1990 was controlled by the Muslim Brotherhood. Atta had the sort of profile the Brothers were looking for: a smart, upwardly-mobile young man, with a technical specialisation, but no place to go. His personal advancement in Egypt was blocked due to his family not having the right connections. He loved his country but, like his father, hated his government's ties with America. Egyptian education would not have provided him with a balanced view of history, to say the least. "He would have been taught the anti-historical Islamic view that everything before Islam is cancelled, and after Islam, the world is divided into truth versus falsehood," an expert on Egyptian education told me. He would have acquired the view that the world was divided into the House of Islam, in which Muslim government rules and Muslim law prevails, and the House of War, the rest of the world, still ruled by infidels. When Atta began living in Hamburg, did he see his benign environment as a House of War? Did he recoil from it?

The tuhh campus is around the corner from Marienstrasse 54. Its modern design makes it look like a foreign body in this area of postwar drabness. How did Atta's architect's eye respond to the modern ugliness of this university? He was surrounded by ugliness pretty much everywhere he went in this city: his neighbourhood, the university, the mosque where he would meet his allies in the Steindamm district is also a nondescript building in a seedy neighbourhood. (The only exception is the wealthy Ottensen district where he had a part- time job in a fashionable architecture firm.) As I walk towards my meeting with Rüdiger Bendlin, the press spokesman for the TUHH, I notice the names and photographs of some of Atta's allies are still taped to the door of the campus cafeteria. I watch the claustrophobic campus for a while and wonder how anyone could spend nine years here.

Bendlin is a jovial man in his early 40s. He looks exhausted-this is only a few months after 11th September-and seems to welcome the excuse to ignore insistent phone calls, as he chain-smokes for an hour or so under the pretext of giving an interview. He is talking to me because the man I had really hoped to interview, Atta's professor and thesis supervisor Dittmar Machule, is no longer willing to talk.

Bendlin recalls how, in the middle of the night of 12th September, the university's chancellor Jorg Severin was woken by police. Acting on a tip from the FBI, they informed the disbelieving academic that students from his university were the leading suspects in the attacks in the US. The same night, police began to examine university files, records, e-mail accounts, computers. They searched the now empty flat in Marienstrasse, and other houses. When it was confirmed that Atta had been a student at TUHH and Ziad Jarrah at the University of Applied Sciences in Hamburg, the latter university's president, Hans- Gerhard Husung, said to CNN this was "very unpleasant and disturbing news. It's just an accident it happened in Hamburg. We are ashamed about it; but if you read the evidence correctly it could have happened anywhere in the world." Bendlin, from the TUHH, also speaking to CNN, had been more emotional: "It's terrible. We don't know how to bear it. We always ask ourselves if we did something wrong."

Today, he feels more of a distance from the events of several months ago: "Atta's German was excellent, almost without an accent. I wish German students were as eloquent." The TUHH, he explains, has about 5,000 foreign students, 10 per cent of them from Arab countries (university tuition is free in Germany, even for foreign students). The integration on campus has always been good, and even now, he adds, there is no mistrust among the different nationalities. "Many students return to their home countries, with our excellent degrees in engineering and other technical disciplines." Later, I talk to a few students in the cafeteria. Most of them are German, and they tell me that "Muslim students keep to themselves." On campus, I observe foreign and German students in separate groups. But this might just have been chance.

Before I leave Bendlin's office, he provides me with the details of some of Atta's German friends. I want to talk to them to establish a chronology of Atta's life in Hamburg and to try to find out what sort of person he was, or seemed to be, to them.

In the early 1990s, the department of urban planning accepted only graduates. Many were sociologists or political scientists, some were architects. This mix made for a very political department, and one that was quite different from the purely technical courses of study in the rest of the TUHH. In 1992, Atta enrolled here as a full-time student.

He lived in a student residence close to the university and seems to have had no trouble making friends with German students-as long as they were male. Volker Hauth, a fellow architect who knew Mohammed well from 1994 to 1996, says that "he had no experience with women," and was so awkward and abrupt with them that many found him rude. But perhaps this applied only to non-Muslim women; when they travelled to Aleppo together as part of their studies, Hauth recalls a "tender friendship" between Atta and an attractive young Palestinian architect. "She was very self-confident, and teased Mohammed, saying that all Egyptians are pharaohs." He confided in Hauth that, sadly, she was "too modern." Hauth thinks that Atta was a virgin to the end.

Hauth is over six feet tall. He towered over Atta who was quite small, although with the years he put on some weight and became more muscular. They often talked about religion: Hauth is a committed Protestant, and felt that this helped him understand his friend's seriousness about belief. I ask him to describe Atta's character: "He was highly intelligent, diplomatic, knew how to talk to people and get their attention. Extremely religious. When it came to Islam, he had no sense of humour. Over the years, he became more and more isolated and bitter, developed a tunnel vision. I don't see him as a fanatic, I see him as someone who stood by his convictions, which grew stronger by the day. He cared about justice, the poor... He was very critical of Mubarak's government. In one of the classes, he gave a talk about Egypt's internal policies, in which he attacked the government as being undemocratic and militaristic. He told us that the power structure divides the country into friends and foes of the government, without any room for dissent. He seemed very engaged but also analytical and persuasive."

Yet Hauth's Egyptian friend, who was so critical of his own government, clearly felt much better in his own country. "He didn't feel at home in Hamburg. In Arab countries-Egypt, Syria-he was much more relaxed, lively, funny. In Germany, he was uptight, strict. And always calm, measured. Yet, increasingly, I felt a sense of despair in him, on a personal level."

In December 1994, Hauth and Atta travelled to Aleppo in Syria. They spent three weeks together, staying at the Al Bustan hotel in the western part of the city. The purpose of their excursion was to pursue the idea of co-writing a thesis about Aleppo. But there were tensions: "As a north European, I felt the need to be alone sometimes. Atta didn't understand that. He was insulted, demanded constant closeness. We also argued when I informed him that, in the end, I had decided not to write the thesis. I felt that as a westerner, it was not my area. I couldn't contribute any useful ideas. It was all about the conflict between traditional middle eastern structures and western influences." But while they were looking for ideas and material, Hauth took a lot of photographs in Aleppo, including of Atta: "He loved being photographed. But he asked me for all the pictures I took, and I think they ended up in his thesis."

Was this diligent student more than a pious young man with a burning sense of justice? Was he becoming radicalised? Under whose tutelage? Hauth thinks he remembers that Atta had a beard by 1994 and that he had told him that in Egypt, "men with beards are fundamentalists." But, strangely, Atta never told his friend about his pilgrimage to Mecca in 1995.

Much has been made of Atta's trips to Prague in 2000 and 2001, before and during his flight training in the US. According to official Czech sources, he met with the Iraqi vice-consul, and allegedly high-ranking intelligence officer, Ahmed Khalil Ibrahim Samir Al-Ani on April 8th 2001. On an earlier occasion, in May 2000, Atta had arrived at Prague airport from Germany without a visa, and was turned back. He then reapplied for a visa in Bonn and returned to Prague by bus, on 2nd June. After one day he flew from Prague to Newark, his first trip to America.

While talking to Hauth about Aleppo, I discover that Atta had been to Prague as early as 1994, also without a visa: the students had bought the cheapest tickets-Czech Airlines-from Hamburg to Damascus, with a stopover in Prague. While stopping there, they were able to walk around Prague together. Hauth recalls that Atta liked the city very much. But, when flying back, Hauth's German passport enabled him to leave the airport and spend the night in a hotel, while Atta was not allowed to leave the transit area, as he didn't have a visa.

Hauth also met Atta's father once, on a trip to Egypt with Mohammed and two other German students. The father ("a nice man") picked them up from the airport, Atta stayed with the family, the German students stayed elsewhere. "There seemed to be serious tension between father and son." This was 1995: Atta had won a scholarship from the prestigious Carl-Duisburg Gesellschaft, to spend three months in Cairo writing a research paper on public policy in developing countries. In his application, he had written: "Since I have been living in Germany, I have tried-consciously or subconsciously-to understand, as an outsider, how this so-called first world sees us and how it treats our third world." His resulting report paper was evaluated as "superb."

By 1996, the two friends had lost touch. Yet, sometime in 1996 or 1997, Hauth bumped into Atta in a wealthy area of Hamburg called Uhlenhorst, near the home of a man called Mamoun Darkazanli, a businessman of Syrian origin, who has been under police surveillance as a bin Laden financier and possible member of al Qaeda. It was also in 1996 (11th April) that Atta had written a will (signed by two witnesses) the wording of which indicates his leaning, at this time, towards a very orthodox, perhaps archaic, version of Islam. One clause indicates that he may already have decided to become a martyr: he commands his mourners to pray that he be forgiven for what he has done in the past-but "not this action." But even if he had, by that point, opted for martyrdom, he had not yet envisaged that his death would leave no corpse, for most of the clauses contain precise instructions regarding the treatment of it. The will stipulated that women would not be allowed near his corpse, nor were they to mourn him.

Although he had announced his interest in writing a thesis about an old quarter of Aleppo as early as 1994, it was not until five years later, in March 1999, that Atta began seriously working on it. (This freedom to remain enrolled while doing absolutely nothing for years is a peculiarity of German universities.) Atta continued to take courses and come to lectures, but he seemed to be in no hurry to complete his degree. Friends said he often disappeared for longer periods on "family visits." He was also often seen at the radical Steindamm mosque.

Professor Dittmar Machule, Atta's thesis advisor, finally agrees to talk to a small group of journalists who have been "persecuting" him since 11th September. I am one of them. The press conference is also attended by Crilla Wendt, a woman who can tell us a lot about Atta: she spent hours with him, editing and rewriting his thesis.

Machule is a very agile man of 61 who seems to revel in the media attention. He has clearly spent much time thinking about this, and, in addition to reporters, has been questioned at length by the FBI and the BKA (German intelligence). The much coveted thesis-the only detailed written record left by Atta-is in his hand, but we are not allowed to read it: it is considered evidence, although one wonders why. Suddenly, it strikes me as ludicrous that Atta's ideas on how to preserve an old quarter of Aleppo are regarded as a window into his terrorist's mind.

The professor "retells" the thesis to us in his own words. Its 162 pages can be simplified as follows: the old quarter is a mess of old and new, traditional and contemporary. For example, people living in new six-storey buildings can look down into the courtyards of old low houses, thus interfering with the privacy of family life. Arab shopkeepers are being pushed out of their natural habitat, the narrow streets of a souk. Here is a proposal that shows how tradition can be upheld. This includes, apparently, a suggestion to keep women inside their houses.

The thesis (which had scored a very high mark), Machule says, contains "not a hint of anti-Americanism." There is a chapter on Syrian-Israeli relations, "dealt with very rationally." As we are not given quotes, I have no idea what this means. There is also no religious content of any kind-unless you count the inscription on the front page. "My life, and my death, belongs to Allah, master of the universe."

Machule clearly liked this student very much; describes him as smart, alert, dedicated, serious. If he noticed any peculiarities about him (like not shaking hands the way "we Germans do"), he put them down to Atta's being religious, or an Arab, or both. He told us how Atta would interrupt a conversation and go to pray. He admits that he was impressed by this earnestness of purpose. In fact, he hoped that "this very religious young man... would one day go back to his country as a sort of ambassador between the secular west and the religious east, that he would be able to explain our cultural differences."

Yet Atta, the future ambassador, refused to shake hands with Crilla Wendt after his successful oral defence of the thesis she had helped him write. In fact, he almost refused to work with her during their last session; she practically had to force him to finish the job. "In 1999," says Machule, "I noticed that he had stopped smiling altogether, had become harder. After the defence,he never came in to tell me what he was up to, as I would have expected a student of mine to do." A female student who had occasionally chatted to him in 1994 to 1995 and knew him to be very reserved with women, was shocked when she saw him again in 1999: "He completely ignored me, twice, walked right past me, as if I didn't exist."

Martin Ebert, another German friend of Atta's who knew him well from 1993 until 1997, sheds a different light on their university environment: "It was very anti-American, very politically correct. Machule has a tendency to treat foreigners differently, to help them, to give them better grades. He sees a cultural pattern, not a real person. The department was a centre of political activity. Mohammed felt comfortable there. I remember one day, in the cafeteria, he told a story about an old street in Cairo covered with bubble gum and bottle caps. Everyone at the table understood; he was saying-they were all saying: America is rolling over us.'"

Ebert describes Atta as mostly reserved and passive in conversation, never aggressive. He is originally from east Germany, and I wonder whether Atta understood the difference between east and west Germany. The issue must have been much discussed at the time, shortly after German reunification. "No, he didn't really care. Or at least he didn't show it."

After successfully defending his thesis, Atta lingered in Hamburg for almost another year, until spring 2000 and his first trip to the US. During this period, Crilla Wendt met him accidentally in Harburg and asked what he was doing. He had a plan to work in Egypt, he replied wistfully. But it had fallen through. In truth he was living in a poor suburb called Wilhelmsburg, among a mostly Turkish population. He was already involved in the active preparation and planning of the attacks: money transfers, passports, travel, flight training contacts. The conspiracy would have been entering its final stage. But there will be small unexpected hiccups. For example, Atta will be stopped for speeding, in Florida and almost lose his licence-twice. His Dutch flight instructor, Rudi Dekkers, will want to speak to him in German, but Atta will turn away, pretending he doesn't understand. He and his friends will be rude to a hotel manager, saying: "We don't have time, we have a mission." "What sort of mission," the hotel manager will laugh, "Islam?" They will storm out. Atta will insult his first American landlords, especially the woman, and get kicked out of the house. The reserved, unemotional Mohammed El-Amir of Harburg will become the obnoxious, and finally lethal, Mohammed Atta in the US. Rudi Dekkers will describe him to me as an "arrogant son-of-a-bitch."

But the question remains: why Hamburg? I got one answer from a Hamburg policeman, who showed me the city through his eyes. He took me to the seedy sections (even the seediest of which are unbelievably clean) and complained about the city's ultra-liberal justice system which "ties my hands and doesn't allow me to deal effectively with even the most obvious of suspects, especially if they are foreigners." He spewed statistics proving that this city has the highest crime rate in Germany, and the highest influx of dangerous drug dealers. The policeman, a social democrat and a native of Hamburg, believes the city's kid-glove attitude to crime makes it an ideal haven for both terrorists and criminals.

So perhaps Hamburg was chosen for these very obvious reasons: its leniency and the freedom to register as a student for many years, while doing other things. Mounir Motassadeq, a Moroccan friend and TUHH student colleague of Atta's, who was under surveillance after 11th September, agreed, in November 2001, to answer just one question over the phone: "Did Mohammed feel comfortable in Hamburg?" "Yes," he replied with a chuckle. "He did." Comfortable, that is, not as a human being but as the professional terrorist he became while he was living there.

A month later, Motassadeq was himself arrested, in connection with the attacks. And in July this year, the BKA arrested and interrogated a newly discovered Hamburg terrorist cell, with links to Atta's group. After the interrogations they were released, but remain "under observation." A recent editorial in Die Welt asks: "Why Hamburg, again and again?"

Perhaps the role of Hamburg, the most liberal of western cities, is to highlight the impossibility of an understanding between militant Islam and western values and achievements. The terrorists' "Hamburg years" were the years of their mutation from ordinary young men to dedicated mass murderers, from sleepers to recruits for martyrdom, their real identity remaining a secret to their well-meaning German friends, teachers, employers, even partners.

Finally, I asked Martin Ebert a hypothetical question: if Atta had somehow survived the attack and he had a chance to see him again, what would he say or do? "Nothing. There is absolutely nothing to say."