As the US confirmed this week that it is holding a top-ranking official from Osama bin Laden's al-Qaeda network, European investigators have admitted they are unsure just how much of the organisation has been dismantled in Europe, writes Lara Marlowe.
US Secretary of Defence Donald Rumsfeld did not hide his delight earlier this week when he confirmed that the US is holding Abu Zubaydah, a top aide to Osama bin Laden.
Nearly seven months after the September 11th attacks, Washington needed to show progress in breaking the al-Qaeda network.
Abu Zubaydah, a Palestinian in his 30s who was born in Saudi Arabia, had welcomed foreign volunteers to the network in Pakistan, then sent them on to camps in Afghanistan. He was shot three times in the groin when he was arrested along with dozens of Islamic militants in Pakistan in late March and is believed to be on a US base now.
Abu Zubaydah may have inside knowledge of future al-Qaeda attacks and may even know where bin Laden is.
Much of what is known of his role has come from suspects caught in Europe. They include Yacine Akhnouche (27), an Algerian arrested near Paris two months ago. Akhnouche's phone had been tapped since his number was found on another Algerian follower of bin Laden in Spain in June 2001.
He told French intelligence agents that he was having second thoughts about his Islamist commitment and provided a wealth of detail about the network. It was Abu Zubaydah who arranged Akhnouche's travel to Pakistan and Afghanistan, where he'd seen the "20th hijacker", Zacarias Moussaoui, and the would-be shoe-bomber, Richard Reid, in the same training camp in 2000.
The interrogation of Akhnouche and dozens of other Muslims arrested in Belgium, Italy, Spain, France, Germany and Britain could prevent further atrocities like September 11th. But the fact that most have been released without charge raises questions about anti-Muslim prejudice and human rights abuses.
Despite hundreds of arrests in the US, not a single proven al-Qaeda operative has been found there since the attacks. Nor are European investigators satisfied they've uncovered everything. August Hanning, the head of the German intelligence service BND, told Le Monde that despite 27 investigations into al-Qaeda's workings, "we still don't know exactly how their structures operate in Europe. We don't know how much has been dismantled."
The task is complicated by political tension, for example, between Washington and Paris. France wants six French citizens held in Guantanamo to be tried in France and opposes a possible death sentence for Zacarias Moussaoui. And there are turf battles between intelligence services.
French investigators say the Americans have told their Pakistani allies not to co-operate with Paris. The French also complain of what they see as British complacency towards Islamic fundamentalists.
Paris has tried for years to extradite Rachid Ramda, an Algerian held in London, to try him on charges of funding Algerian GIA bombers in France.
Washington is sometimes over-eager. Britain released Lotfi Raissi, an Algerian airline pilot who lived in London with his French wife, after five months' detention.
The US wanted to extradite Raissi, but could provide no evidence of links with al-Qaeda. Washington also wants London to hand over Abu Doha, an Algerian cleric believed to have planned an attack on Los Angeles Airport, and Khaled al-Fawaz, an Egyptian who Washington claims transmitted the order to blow up US embassies in Nairobi and Dar es-Salaam, where 224 people were killed in August 1998.
Sometimes information comes from unexpected quarters. A few weeks ago Iranian officials notified the French embassy in Tehran that Sylvie Beghal, the French-born wife of Djamel Beghal - already imprisoned in Paris - had escaped from Afghanistan and was living in a Tehran hotel with her three children.
Mrs Beghal refused to see a consular official because he was not Muslim. The embassy dispatched a French-speaking Iranian woman in a chador to arrange the family's repatriation.
French police met Mrs Beghal's at Charles de Gaulle Airport near Paris, then kept the petite, blonde 30-year-old French woman in custody for four days so a judge could question her about her Algerian-born husband. Only then was she allowed to visit him in Paris's La Santé prison and return to the couple's flat in the suburb of Corbeil.
Djamel Beghal was arrested in the United Arab Emirates last summer. French authorities believe he may be the most important al-Qaeda member in custody in Europe. He is accused of planning to crash a helicopter loaded with explosives into the US embassy in Paris.
The Beghals moved into the "Algerian" neighbourhood of the Afghan city of Jalalabad in November 2000. They had spent the previous two years in Britain, where Djamel reportedly recruited Moussaoui and Reid.
Until September 11th, Mrs Beghal told investigators, she and other foreign wives in Jalalabad knew only that their husbands were undergoing military training. A year ago she comforted her pregnant friend, Amal Trabelsi. Amal's husband, Nizar, a Belgian of Tunisian origin who had been a professional football player, told Amal that he was "going to Europe to do a bombing" and "probably wouldn't come back".
Trabelsi is one of several dozen alleged al-Qaeda members arrested in Belgium, the Netherlands and France after Djamel Beghal's revelations.
Police in Europe believe they've prevented two, possibly three, al-Qaeda attacks. Five men will go on trial in Frankfurt on April 16th, charged with plotting to bomb the Strasbourg Christmas market in December 2000. The German prosecutor says all five spent time in training camps in Afghanistan. French police say Tarek Maaroufi, a Belgian of Tunisian origin who was arrested four months ago in Brussels, was involved in the Strasbourg plot. Maaroufi is charged with recruiting for al-Qaeda.
Al-Qaeda's plans to attack the US embassy in Paris were apparently abandoned when Djamel Beghal was arrested in July 2001. The discovery of a hole in an underground pipe near the US embassy in Rome in February, and the arrest a few days earlier of eight Moroccans, led to speculation that the Rome embassy was also threatened.
The assassination of the Afghan opposition commander, Ahmed Shah Massoud, days before September 11th showed close co-ordination between al-Qaeda members in London, Brussels and Afghanistan. An al-Qaeda computer purchased by a Wall Street Journal correspondent in Kabul in January contained the original of a letter to Massoud sent by assassins posing as journalists.
The letter of introduction was signed by Yasser Al-Siri, an Egyptian arrested in Britain last October. Massoud's killers were later identified as Abdessatar Dahmane, a Tunisian who lived for 14 years in Belgium, and Bouraoui al-Ouer, also Tunisian. Both were reportedly recruited by Tarek Maaroufi.
Al-Qaeda appears to have been deeply implanted in Germany. Three of the September 11th hijackers were students in Hamburg in the months preceding the attacks, and there is evidence that a Moroccan named Mounir al-Motassadek, arrested at the end of November, transferred money for them.
The extremist network earned money from stolen and fake credit cards in Spain, where eight north Africans have been arrested by Judge Baltasar Garzon. Mohammed Atta, the hijacker who crashed into the World Trade Centre, spent nine days in Spain in July 2001, staying near the Senasa flight school, which teaches students to fly Boeing 757s.
Most of the European al-Qaeda members were indoctrinated in mosques in Britain, often by Omar Abu Othman (41), a Palestinian better known as Abu Qutada and considered the group's spiritual leader in Europe. Although he was under round-the-clock surveillance, Abu Qutada vanished in December, just before special "anti-terrorist" legislation was enacted. A French source in London suggests he may have been a double agent.
In addition to the six Frenchmen held in Guantanamo, French police believe up to 100 of theircitizens, mostly of north African origin, fought with the Taliban and may now try to return to France.
Muslim suburbs of Paris and Lyons provided the largest number of Westernised foot soldiers for bin Laden.
On Christmas Eve Hervé Jamel Loiseau (28), the son of an Algerian immigrant and a French woman, was found frozen to death in the mountains of Tora Bora. Loiseau, like most of the Frenchmen now held at Guantanamo, was among 53 Islamic activists arrested on May 26th, 1998, in the run-up to the World Cup. They were released for lack of evidence.
Brahim Yadel (31) was Loiseau's closest friend and spent six months in prison after the World Cup round-up. His mother, Atika, was notified at the beginning of February that Brahim is held at Camp X-Ray. His brother-in-law, Rachid, told the Journal du Dimanche that Brahim was head waiter in a Paris restaurant, but resigned six years ago because he did not want to serve wine. He and Hervé Jamel said they were going to live in Saudi Arabia to study Arabic and the Koran. Investigators believe both went straight to bin Laden's camps in Afghanistan.