By Matt Cottingham
Assistant Producer, The New Al-Qaeda
The ingredients are simple: widespread anger at US-led policies in the Middle East, the proliferation of information about bomb-making on the internet and the ability of Islamist extremists to blend into Western society. This potent cocktail has created the new al-Qaeda, the subject of Peter Taylor's new BBC Two television series.
It is the most sacred night in the Islamic calendar, celebrated as the night the Holy Koran was revealed to the Prophet Muhammad.
It was also the same evening that US troops invaded Falluja, at the time a key base of the insurgency in Iraq.
Along with reporter Peter Taylor, I had gone to the Regent's Park mosque in Central London where thousands of Muslims were gathering for prayers.
Within minutes of our arrival, a group of angry, young radicals had taken over the courtyard of the mosque and we were confronted by the vitriol of the "War on Terror".
"We need more American soldiers, more British soldiers, we want them killed," was the cry. "We need to raise the sword and we need to have the heads rolling."
Our presence was immediately resented, the camera ripped from my hands and vicious abuse hurled in our faces. Fortunately, a huge man from the mosque authority stepped in.
Radicals chanting at worshippers arriving at Regent's Park's mosque
With blows being aimed in our direction, we were helped away as the mosque authorities called the police to tackle the extremists.
You do not have to look far to discover what is driving the hatred. The internet is swarming with websites that triumph al-Qaeda's propaganda.
And if you dive beneath the surface of the rhetoric you quickly find its online caliphate - a virtual safe haven for al-Qaeda that allows it to recruit, train, fund raise and mobilise.
Here is the lifeblood that is driving the new al-Qaeda after the US razed its training camps in Afghanistan.
Videos showing how to make suicide vests, build mortar bombs, carry out hi-jacking, build homemade explosives - the list of resources online is endless.
It is now possible to learn how to prepare for jihad (Holy War) against the West from the safety and security of your own bedroom.
Many commentators presumed that because al-Qaeda had been dispersed after the war in Afghanistan, it had become weaker. Some even claimed that it no longer existed.
An examination of the attacks in Madrid had already shown this was a dangerous assumption to make. As the intelligence services focussed on stopping another 9/11 spectacular, the footloose group of individuals responsible for Madrid had slipped under the radar.
Although the investigation into the London bombings is in its early stages, it appears likely a similar group acting independently of Osama Bin Laden may be responsible.
These men are often called takfiris - Muslims who seamlessly embrace Western lifestyles and dress so they escape the preying eye of the intelligence services.
Some of the Madrid bombers were even recruited in prison, the criminal underworld providing apt cover for a wannabe terrorist.
Dressed in fashionable labels and with the internet at their fingertips, jihadis have the vital ingredients for home-grown terrorism. Three of the members of the cell were The Drug Dealer, The Estate Agent and The Telephone Man, giving the second film of the series its title.
Pakistan plays a pivotal role in the "War on Terror". Early last summer President Musharraf of Pakistan ordered thousands of troops into Waziristan, the rugged, mountainous border region with Afghanistan where Osama Bin Laden is assumed to be hiding.
Bin Laden's training camps in Afghanistan were destroyed in the aftermath of 9/11. But the most elusive man on the planet is fundamental to the new al-Qaeda. His role is as a figurehead, a global inspiration of jihad against the West.
Almost every radical Islamist website I have ever looked at (and there have been many) has a picture of Osama Bin Laden somewhere.
In Pakistan more than 500 al-Qaeda suspects have been arrested and interrogated in recent years including a number of its leaders.
Although the Pakistani intelligence services deny using torture, they blindfold their suspects and often interrogate them for up to 48 hours at a time. The information they have collected has been fundamental to understanding how al-Qaeda has changed
Naeem Noor Khan's computer was the hub of al-Qaeda's communications network. His capture (by the Pakistanis last year) forced the United States to raise its security level for the Presidential election and led to several suspects being detained in the UK.
Naeem Noor had lived in Reading and studied at City University in London. The road between Britain and Pakistan is well known to al-Qaeda.
According to Pakistani intelligence, three of the London bombers travelled there over the last couple of years. It appears they may have met people in Pakistan who brought the plan for the attacks in London to fruition.
Naeem Noor's cousin is a man called Babar Ahmad.
US prosecutors say he pioneered al-Qaeda's activities on the internet. Whilst living in Tooting, south London, they allege he set up its first website in the late nineties, all in the English language.
According to an American indictment filed against Ahmad, he operated the website from Imperial College, London and hosted it in the US. It was all entirely legal.
Dr Muhammed al-Masari is a Saudi Arabian dissident whose website posts reports from al-Qaeda's frontline in Iraq and hosts videos of the suicide bombings and beheadings that take place there.
Dr al-Masari's website hosts videos of suicide bombings in Iraq
We tracked him down in Wembley, north London. In a slightly faded hotel near the recently built arch of Wembley stadium, he described how it was impossible to close down his website because he would simply put it up elsewhere on the web and send an email to the members telling them the new address.
Before leaving, he gave an explanation of the longevity of the "War on Terror". It was, quite simply, that al-Qaeda will continue to use weapons invented by the West to attack it.
In Afghanistan it was the military hardware originally donated by America, for 9/11 it was the planes, now it is the internet. This is the chilling core of the new al-Qaeda - while they are inspired by Palestine and the war in Iraq, the tools they use for their attacks are found on our doorstep.
The New Al-Qaeda series was shown from Monday 25 July to Monday 8 August 2005, at 2100BST on BBC Two