Aleppo, Syria. Ten brothers were sitting in the courtyard of their house in one of Aleppo's myriad lanes, with a plastic bag full of small pieces of paper, from which they drew lots. Five of them would stay in Syria and look after all 10 families. The others, the winning five, would enjoy the ultimate prize: a jihadi trip to Baghdad. It was March 2003, the Americans had just started bombing Baghdad and, like the 10 brothers, hundreds of young men were eagerly making their way in cramped buses towards the Iraqi border. Most of them were Syrians, but there were many, too, from other Arab and Muslim nations, all driven by a religious fervour fuelled by the cries of jihad from Muslim scholars.

"Each neighbourhood [of Aleppo] started sending buses loaded with mujahideen into Iraq," says Abu Ibrahim, the second eldest of the 10 brothers, describing those early days of the war. "If someone was unable to go, he would support the jihad by giving his money."

The call to jihad was openly encouraged by the Syrian government, says Abu Ibrahim (a nom de guerre); it also arranged for buses to ferry fighters, speeded up the issuing of documentation and even gave prospective jihadis a discount on passport fees. Meanwhile, the Syrian media were banging the drum for jihad. (The US has repeatedly accused Syria of involvement in terrorism in Iraq; the Syrian government vehemently denies this.) Eyewitnesses recall Syrian border police waving to the jihadi buses as they crossed into Iraq. From the Grand Mufti of Syria, a man known for his religious tolerance for more than 50 years but who issued a fatwa legitimising suicide bombing just before the outbreak of the Iraq war, to a 16-year-old Christian boy from Damascus whom Abu Ibrahim remembers volunteering to fight alongside radical Muslims in Iraq, much of Syria was galvanised to resist the American invasion next door.

Abu Ibrahim, the most radical of his family, was not one of the lucky five of his brothers and had to stay in Syria, which did not go down well with his Bedouin wife. "My wife accused me of being a coward. She accused me of being happy that I didn't have to go."

But a few months later, he and a group of Syrian and Saudi jihadis crossed the border just as the Iraqi insurgency was getting into full swing. Fifty fighters went in total, Abu Ibrahim says now, but after a few months he returned to Syria with three others - the only surviving members of the group.

***

Two years after Syria first encouraged resistance to American troops in Iraq, the country claims to have cracked down on Islamic networks and cross-border activity. But many of these claims have fallen short of expectations, a fact that regional analysts attribute to two different factors. The first is that Syria is dominated by many and sometimes competing security apparatuses, which often behave quasi-independently, according to the leadership and specific agenda of each. The second is that while the Syrians, publicly at least, have considerably reduced the amount of support given to the insurgents and have put hundreds in jail, they are happy to keep the jihadi networks alive for a day when they might be useful again.

Abu Ibrahim was born in 1973 in a village north of Aleppo, close to the Turkish border. His father was a Sufi, a member of a mystical Islamic sect that is reviled by some ultra-conservative Muslims, but Abu Ibrahim never shared his father's tolerant views. "I was born to be a Salafi!" he says, referring to the fundamentalist Sunni school of Islam also called Wahhabism. "Even when I was a child of 10, I would refuse to shake the hands of the Sufi sheikhs who visited my father."

Abu Ibrahim's face is lined from time spent in Syrian and Saudi prisons. He looks older than his years, and has a short, scrubby beard, his larger beard having been shaved off by Syrian security officers during one of his detentions. (My conversations with Abu Ibrahim were conducted under extremely close monitoring by the Syrian security services.) He is small and slight, but says he can fight five men alone. He keeps repeating that pride and honour are the most important things in life.

Abu Ibrahim is furious at American imperialism, outraged by Palestine, repelled by the secular Syrian regime. He is angry, as many Arab young men are, and like many of his generation, has grown to see the holy war of jihad championed by Osama bin Laden as the only way to salvation.

Abu Ibrahim's goal is to re-establish the Islamic caliphate, and he sees the rule of the Taliban in Afghanistan as one of the few true Islamic governments since the time of the Prophet. He thinks the Qur'an is "a constitution, a law to govern the world". His views are severe, narrowly defined and impractical. But it is important to understand his anger and his contradictions, because Abu Ibrahim is as close to al-Qaida as it is possible to get.

***

At the age of 22, Abu Ibrahim's rebellious ideas against his father's Sufism were nurtured by a group of radical Salafis who flourished in the villages around Aleppo, in Syria's Sunni heartland. "I met a group of young men through my wife's family who spoke to me the true words of Islam; they told me Sufism was forbidden and that the Shia are infidels."

A year later, he decided to go to Saudi Arabia, taking some of Aleppo's famous textiles from his family's workshop and trading them in Riyadh. His seven years in Riyadh were prosperous ones; at times he was sending home $12,000 a month. But while he was there, he also met other young men with whom he started learning the Qur'an. "God provided for us," he says. "We were banned from preaching publicly. We read the mother of all books and then we started to know the truth. Everything was done in people's homes."

Young Saudis, he felt, were educated and worldly and they had what he considered a better understanding of the truth. But he also saw that they had the money and resources to put into practice what they were talking about. "When they went to fight in Afghanistan, they got a government salary, and they also had the resources to fight in Chechnya, the Balkans and now in Iraq."

In 1999 Abu Qaqaa, a charismatic Syrian religious sheikh, was preaching a radical version of Islam in Aleppo. In Saudi Arabia, Abu Ibrahim heard about the sheikh, who wore a salwar kameez, a relic of his time spent with Arab mujahideen in Afghanistan, and was impressed. "We were Wahhabis. Abu Qaqaa was preaching what we believed in. There he was saying these things: people with beards, come together. I was so impressed."

Returning to Aleppo, he became Abu Qaqaa's right-hand man. While in Saudi Arabia, Abu Ibrahim had been given training in video montage and digital photography at a private Saudi production company that specialised in the dissemination of radical Islamic propaganda. Now he helped to tape and copy Abu Qaqaa's sermons and to distribute CDs. They would travel to Damascus and to Saudi Arabia together. By 2001, Abu Qaqaa had attracted about 1,000 young men to his cause, though everything at this stage was underground and secret. "No one knew about us. But September 11 gave us the media coverage. It was a great day. America was defeated. We knew they would target either Syria or Iraq and we took a vow that if something happened to either countries, we would fight."

Two weeks after September 11 they decided to have a celebration. They called it "the Festival of America the Wounded Wolf". They made a video of martial arts fighting, including hand-to-hand combat and training exercises in which they jumped off 8m-high walls. During this time, Abu Qaqaa was arrested by the Syrian authorities, but was released within hours. "We thought, 'Oh, how strong our sheikh is that they do not touch us,' " Abu Ibrahim remembers. "How stupid we were."

By 2002 they were organising anti-American "festivals" twice a week. Food and CDs of sermons were distributed freely and the group, now calling itself "the Strangers of Cham [the Levant]", grew more popular. One festival was called "the people of Cham will now defeat the Jews and kill them all".

"Officials used to come to these festivals, security chiefs, advisers to the Syrian president. We had Palestinian flags and scarves saying, 'Down America'. It was very well organised - we tried to inspire young men and encourage them. We even had a website." The group grew bigger and stronger, its reputation and CDs reached other Arab countries, and young men from Ramadi, Salahuddin and Mosul provinces in Iraq came to seek them out. Meanwhile, money started pouring in from Saudi Arabia and other Gulf states.

Abu Ibrahim and his friends were tough, and created a phalanx cadre around Abu Qaqaa. They would raid houses and throw people out of their beds if they heard that they had said bad things about him. "We were exactly like the Amen [the state security services]," he says. "Everyone knew us. We all had big beards. We became thugs."

But slowly they began to suspect that their charismatic leader was a stooge for the state security and had long been an agent for them. "In the 80s, thousands of Muslim men died in Syria for much less than we were saying. We asked the sheikh why we weren't being arrested. He would tell us it was because we weren't saying anything against the government, that we were focusing on the common enemy, America and Israel."

Their suspicions hardened when they discovered that Abu Qaqaa had provided the state security with a list of all the Wahhabis in Syria. They had begun to split from him and were thinking of taking their revenge when the Americans invaded Iraq.

With the beginning of the Iraq war came the jihad frenzy, and the busloads of mujahideen. Saddam's government considered them manna from heaven; as the Americans rapidly advanced, they branded them Arab Saddam Fedayeen, and gave them weapons and basic training. But when Baghdad fell, the stories the Syrians brought home were bad. Often the Iraqis shot at them or handed them over to the Americans.

Abu Ibrahim, who had his own group of jihadis and was actively ferrying people across the border during this time, said that his Iraqi contacts "asked us to stop sending people, they said, 'There are Shia everywhere, Americans,' and they couldn't do anything." According to Abu Ibrahim and other sources in the insurgency, the quick American invasion of Baghdad and the collapse of the Iraqi army shocked the religious leaders and a debate started as to whether they should start a jihad against the Americans or whether this would only bring Saddam back to power, an option that was as bad for the Islamists as the US occupation.

But the Syrian authorities didn't want cross-border traffic in fighters to stop. The security services pressured them to keep sending people. "Why were they so keen for us to go and fight in Iraq?" asks Abu Ibrahim. "So we would die there?"

***

In the summer of 2003, the insurgency in Iraq began to organise itself and there was a further call for men. Places to stay and a network of routes, weapons and safe houses had been established. "We had specific meeting places for Iraqi smugglers. They wouldn't do the trip if we had less than 15 fighters. We would drive across the border and then into villages on the Iraqi side; and from there the Iraqi contacts would take the mujahideen to training camps." Syrian recruits could usually skip the training given to others, as every young Syrian man has to do two years of military service."It is mostly the Saudis who need the training," says Abu Ibrahim.

The main bulk of the insurgency at that time was led and organised by Iraqis who functioned in cells, often with no coordination. They focused mainly on ambushes and IED (improvised explosive device) attacks. "Our brothers in Iraq worked in small groups. In each area men would come together organised by religious leaders or tribal sheikhs and would attack the Americans. It was often us who brought them all together, when we met them in Syria or in Iraq. We would tell them, 'But there is another brother who is doing the same thing - why don't you coordinate together?' Syria became the hub.

"Young men are fighting with zeal and passion, there are Saudi officers, Syrians, Iraqis, but not those who fought for Saddam. The man who is leading it for the most part", says Abu Ibrahim, "is Zarqawi."

The emergence of Abu Musab al-Zarqawi was the big breakthrough for the insurgency, especially after he was endorsed by Bin Laden late last year. Zarqawi, a Jordanian-born radical Islamist, then changed the name of his disparate group of insurgents to al-Qaida of Jihad in Mesopotamia, and funds started pouring in from Saudi Arabia. In Iraq, many different factions of the insurgency placed themselves under Zarqawi's banner and a joint treasury of jihad, called Bayt al-Mal, was founded.

"Until six months ago, Zarqawi and Osama bin Laden were different: Osama did not legitimise the killing of Shia. Zarqawi did that. Six months ago, Zarqawi gave the beyaa [allegiance] to Bin Laden. Anyone, Christian Jew, Sunni, Shia, who cooperates with the Americans, can be killed. It's a holy war." (Our conversation took place before Zarqawi was supposedly injured near Ramadi last month.)

By January 2004, Syria was coming under increasing pressure from the US to halt the jihadi traffic into Iraq. Jihadi cell leaders in Syria were summoned to Amen [internal security] headquarters and told that it could not continue. Passports were confiscated; some were detained for a few days.

It may not be terribly significant in halting the violence, however. According to Abu Ibrahim, insurgents in Iraq are not presently in need of fighters, but funds - which usually come from wealthy Saudi young men.

"Our brothers in Iraq are asking for Saudis. The Saudis go with enough money to support themselves and their Iraqi brothers. A week ago we sent a Saudi to the jihad; he went with 100,000 Saudi riyals [$27,000]. There was a celebration among his brothers there!"

Four weeks ago, US troops in Iraq launched an operation just inside the border with Syria, aimed at disrupting the route of foreign fighters; the US army claimed that 100 fighters were killed. Abu Ibrahim is unmoved to learn of the assault. "They think jihad will stop if they kill hundreds of us in Iraq. They don't know what they are facing. Every day, more and more young men from around the Muslim world are awaking and coming to the jihad. Now the Americans are facing thousands, but one day soon they will have to face whole nations."