The war that drove the Soviets from Afghanistan in 1989 left Osama bin Laden with a global army in the making. But it needed a stronger structure and a new mission.

The order he issued to his embattled forces last week to commit suicide rather than surrender starkly illustrates how martyrdom in pursuit of holy war came to be at the heart of that new mission.

And at the heart of its new structure was a mix of careful planning at the centre and the commitment of devoted operatives around the world.

To achieve a presence in what western intelligence services today reckon are 50 countries, al-Qaeda responded to the diverse agendas of Islamist groups from vastly different cultures.

It attracted middle class professionals and petty criminals, political firebrands and economic opportunists. It also lured an army of impressionable teenagers possessed of nothing but despair about the Middle East in particular and the Islamic world in general.

Ulrich Kersten, head of Germany's federal criminal agency, the BKA, believes at least 70,000 Islamic militants have been trained in bin Laden camps.

For ordinary people it is bewildering that so many men could have travelled so widely, received such a range of terrorist training and plotted so meticulously for the best part of a decade without triggering a serious effort by governments to stop them.

Part of the reason for this is that supporters of the "cause" have not necessarily identified themselves as bin Laden followers, and have been recruited by various Islamist organisations in their home countries. Not all actually join al-Qaeda - a process involving swearing an oath (bayat) to bin Laden. In Spain, a group known only as the "Soldiers of Allah" took over Madrid's Abu Bakr mosque in 1994, but had financial ties to al-Qaeda and regularly sent supporters to Bosnia, Pakistan and the Philippines for training, a Spanish investigation alleged last week.

In Germany, al-Qaeda members around Dusseldorf and Cologne used amateur videos of fighting in Chechnya to win recruits. Intelligence officials also say Germany's many mainstream Islamic associations and charitable agencies gave practical support, including money, to al- Qaeda members.

In charge of recruitment - al-Qaeda's "director of external affairs" - was Abu Zubaydah, the sole Palestinian within bin Laden's inner circle, and known to his recruits only by this alias.

Evidence in a court case in the US revealed how Zubaydah worked. "He is the person in charge of the camps. He receives young men from all countries. He accepts you or rejects you. He takes care of the expenses of the camps. He makes arrangements for you when you travel coming in or leaving," said Ahmed Rezzam, an al-Qaeda operative caught in December 1999 with a bomb that he had planned to explode at Los Angeles airport.

Once in the training camps, recruits received a mixture of military and religious instruction. Mohamed Rashed al-Owhali, a Saudi member of the team that in 1998 blew up the US embassy in Kenya, spent four months at Khaldan camp in Afghanistan two years earlier.

Al-Qaeda's military training was - until his death in a US bombing raid in Afghanistan two weeks ago - controlled by Abu Hafs al-Misri, the alias for Muhammad Atef.

"He was the commander, sometimes called Abu Hafs al-Khebir [Abu Hafs the Great]," one of those accused in the east Africa bombings said at his trial this year. Atef, along with bin Laden and Ayman Zawahiri, al-Qaeda's military operations chief, and Abu Zubaydah, formed the military high command.

The trial of Ahmed Rezzam revealed much about the training regime offered by al-Qaeda. Like many others, Rezzam was trained in Afghanistan initially with his own countrymen - while other nationalities trained in their own national groups - under the al-Qaeda umbrella.

During six months of instruction he learned how to use light weapons, handguns, machine guns and rocket-propelled grenades. He was taught how to handle a variety of explosives, carry out sabotage on infrastructure and fight an urban war, including "how to carry out operations in cities, how to block roads, how to assault buildings, and the strategies used in these operations", according to FBI investigators, who in court evidence related their accounts of his answers to their questions.

Vital to all al-Qaeda's most devastating operations to date, Rezzam was taught "cell management" and how to maintain security within a cell of operatives.

"And when you work in a group, each person knows only what he is supposed to do, not more, to preserve your secrets. You must avoid the places that are suspicious or will bring suspicion upon you, such as mosques, and avoid wearing clothing that would bring suspicion on you."

For Mohamed Rashed al-Owhali, the Nairobi bombing was to have been what he described to FBI investigators as a "martyrdom operation" in which it was intended that he would die.

But he first had to become invisible, according to FBI evidence brought before a court in New York. On arriving in Afghanistan, the young Saudi had become Mohammed Akbar and adopted Qatari nationality. While preparing for the bombing he was told he had to go to Yemen to receive a new identity. To make the trip he became an Iraqi, shaved his beard, and received a new passport bearing the name Abdul Ali Latif. While in Yemen he received a Yemeni passport, bearing the name Khalid Salim Saleh bin Rashid. Thus equipped, he passed easily and undetected through five airports on his way to Kenya.

For five years the al-Qaeda cell lived quietly in Nairobi, despite occasional official suspicion. One of them learned how to fly light aircraft, and was a "diligent" pupil, his instructor told the FT.

Even after they received instructions about their mission, their "cell management" training worked perfectly, no sign of their intentions leaking out.

The fact that the truck carrying the bomb was modified became known by means far blander than sophisticated intelligence gathering. The cell member who bought it did so from a long-time neighbour in a suburb of the Kenyan port city of Mombasa. The two attended the same mosque. "I sold it to Mr Sheikh Ahmed Swedan, a businessman in Mombasa," said Said Salim Omar, during the bombers' trial in New York this year. "I knew him for a long time because he's just our neighbour. He lives three blocks from my father's house."

A few days later, he saw the truck, complete with the extra layer of metal enclosing its back, in which the bomb would be housed. He never saw Sheikh Swedan again. But two days after the bombing, his nephew came to see Mr Said - to ask if he could have the vehicle's registration documents.

The Nairobi bombing - together with another on the same day in the Tanzanian capital Dar es Salaam - left 224 people dead and 4,585 injured. Both depended heavily on the advanced training the planners had received in Afghanistan, to where bin Laden returned in 1996, after US and Saudi Arabia pressure forced Sudan's government to ask him to leave.

The east Africa bombers showed their expertise and organisational skills, by using a single planner for both bombings, and a single electrician who travelled between the two cities by bus to wire up the bombs.

In Tanzania, one man was responsible for finding accommodation - a high-walled compound housing the bombers' apparently normal families and within which the bomb-truck could be hidden from view - and another had the role of grinding the TNT explosives. A third drove the truck to the embassy - and martyrdom.

Any documents that might have betrayed the bombers' presence in the city were sent abroad by courier the day before the bombing, and all those not required for the actual attack were ordered to leave the country in advance, with their families.

In Kenya, similar measures were taken. One man wired the bomb then left the country, two drove the truck, while documents betraying the existence of al-Qaeda's five-year-old Nairobi cell were destroyed.

This training was the most potent force bin Laden had to hand. Although his Taliban allies have now lost almost all the territory upon which he has been free to operate, al-Qaeda's network still extends way beyond the borders of Afghanistan. Its skills have been diffused far and wide, and it is far from certain that they depend upon the survival of al-Qaeda's organisation inside Afghanistan.

Few of the bombers had met Osama bin Laden, though all felt they knew what he believed in.

"Osama bin Laden is a sheikh, a scholar and a leader," said Khalfan Khamis Mohamed, the young Tanzanian who had ground the TNT into powder for the Dar es Salaam attack. "I know that people in Osama bin Laden's group are supportive of our group. Because we have the same beliefs we consider ourselves to be part of Osama bin Laden's group. He is our leader in Jihad," Khalfan, who spent 10 months being trained at an al- Qaeda camp, is reported by FBI investigators as having said before his trial earlier this year, after refusing to give evidence in open court.

Thus, belief rather than organisational links were the basis of his commitment to al-Qaeda. The organisation was distant, though remained inspirational and apparently - for those allotted that role by the planners - worth dying for.

Khalfan's assessment of how the "cell" and "the Base" were related is exactly as bin Laden intended. The latter operated by doing little more than feed ideas, occasionally money and sometimes people into the largely autonomous cells. Changed identities, stolen documents, forged passports and numerous aliases have allowed hundreds of terrorists to travel the world, largely untroubled by security checks, as was shown by the ease with which the September 11 hijackers crossed and recrossed the Atlantic and travelled around the US in the year before they struck.

These strategies have occasionally been state-sponsored. During Bosnia's 1992-95 civil war, many Arabs who were already associated with or who subsequently joined al-Qaeda fought for the Muslim-led government in a unit known as el-Mujahid. After the war, the Bosnian government offered them citizenship. Many took it up, some marrying Bosnian Muslim women whose names they adopted, allowing all traces of their past to disappear.

Even for those who had retained their real identities, al-Qaeda's training has included advice on how to overcome hurdles to international travel and by-pass immigration restrictions.

When the would-be Los Angeles airport bomber, Ahmed Rezzam, arrived in Canada in 1994, he admitted to immigration officials that his passport was false. He then claimed asylum, alleging persecution in his native Algeria. It took four years to exhaust the asylum procedures and when he was finally refused entry he simply disappeared, adopting a new identity with the unlikely name of Benni Noris.

The resources of the centre and the resourcefulness of the cells were a potent mixture. Then - and probably still now - the power of al-Qaeda depends upon the fact that its adherents' zeal and readiness to die do not depend on the existence of an organisation at the centre, thus allowing both to be tapped anywhere in the world when the opportunity arises.

Where necessary, relatively open operations appear to have been installed to smooth the flow of information. Lawyers for the US government allege that the public face of al-Qaeda emerged in London in 1994 when Khaled al-Fauwaz secured political asylum in the UK, established an office in the modest suburb of Neasden, opened a bank account and began diffusing literature critical of the Saudi royal family.

They allege that he also arranged finance for the purchase of a $7,500 satellite telephone from Ogara Satellite Networks of Deer Park, New York. Company records show an al-Qaeda operative, Ziyad Khaleel, bought batches of telephone time at 400 minutes at a time, from the company.

The billing information from the number - 00-873-682505331 - shows calls to every country in which al-Qaeda is now known to have had cells.

"Al-Qaeda works like a terrorism holding company, operating on a management-by-objective basis," said Kai Hirschmann, terrorism expert at the German government's federal college for security studies in Bonn. "The [September 11] hijackers were very skilled at autonomously following these objectives." Tomorrow: The money trail