You must first know your enemy
SOME months after September 11, a Czech-based informer told his police handler that a known Iraqi agent had met a young Egyptian in a Prague café in the spring of 2001. The Egyptian was Mohammed Atta, the leader of the 16 terrorists who carried out the suicide attacks on the World Trade Center and the Pentagon.
Though the CIA was cautious about the quality of the intelligence, a specialised unit was set up in the Pentagon by Bush administration hawks to sift through raw intelligence data.
It lent weight to a quest by the administration to establish a link between al-Qaida and Saddam Hussein.
There was one problem with this story. It wasn't true.
This team came up with another key link, concerning a Jordanian, Abu Mussab Al-Zarqawi, one of the most dangerous men to emerge from Osama bin Laden's training camps.
Al-Zarqawi had lost a leg during the war in Afghanistan in late 2001, according to the intelligence the Americans relied on. Saddam, they claimed, had him brought to Baghdad where he was given treatment, including a prosthetic leg.
This gave further credence to the theory that al-Qaida had received direct support from Iraq.
There was one problem with this story, too. It wasn't true.
It seems that Al-Zarqawi didn't travel to Baghdad at that time. It seems he is still walking on his own two legs and the intelligence sources the US relied upon (probably Ahmed Chalabi's Iraqi National Congress) were weaving tales as false as al-Zarqawi's prosthesis.
Next to nothing is known about al-Zarqawi, whom the US now describes as the most dangerous terrorist to emerge from the al-Qaida alliance since Osama bin Laden.
Linked to attacks in Iraq, Morocco and to the train bombings in Spain, nobody is sure of his whereabouts, which groups he controls or even what he looks like.
The "war on terror" makes for a grand-sounding catchphrase, but the image it conjures up of the "shock and awe" military campaigns in Iraq and Afghanistan is misconceived.
Over the past two-and-a-half years, we have seen the West led by the US wielding its awesome military might in Iraq and Afghanistan. In conventional military campaigns, the US is peerless. But how can you target a threat posed by an enemy that is invisible, unpredictable, patient, dispersed, ruthless and committed to the death?
The series of bombing spectaculars linked to Islamist extremists underlines the extent of the threat. The adversary is not one linear organisation, but a series of small groups and cells with loose and tenuous links, which seem to be resistant to infiltration.
That resistance has led to acres of supposition and conjecture, some of it wildly conspiratorial, some of it downright dumb, and some which has been swallowed as convincing and has resulted in military action.
Some of the distortions were created by the US itself. Its invasion of Iraq introduced a diversionary and dangerous overlap between two distinct US aims the desire to find those responsible for September 11 and a long-standing desire of the Bush administration to settle old scores with Saddam.
The second frailty in the war on terror is reliance on the deeply unreliable science of intelligence. Some of the intelligence peddled by the US and Britain on weapons of mass destruction and on Iraqi-al-Qaida links has turned out to be fantasy.
Intelligence is prone to a number of problems. The information itself may be unreliable. Analysts may misinterpret it. Information may be planted or nuanced or distorted to suit a particular end. Paid informers may spice up the information to justify their wages.
Some of the information that has filtered through to the media about al-Zarqawi is as contradictory as the stories about him losing a leg in Afghanistan.
On one reading he heads the Al Tawhid group, which has several cells in Europe. Another reading puts him as the head of Ansar al-Islam, the group that was based in northern Iraq and the target of sustained US bombing during the Iraq war last year.
There is little doubt, however, about the danger al-Zarqawi poses. He is accused of masterminding a number of attacks in Iraq including the suicide bombings in Karbala and Baghdad three weeks ago that killed more than 200 Shi'ite pilgrims.
He is also believed to have been behind a similar attack in Casablanca last year that killed 43 people. And partly because of that connection, he is now in the frame for the Madrid bombing.
But authorities don't even know what he looks like now. It is known he is a product of the Afghan training camps set up by Osama bin Laden and Ayman al-Zawahiri. But the Jordanian remains as elusive as his mentors.
The Madrid train bombings can only be attributed to al-Qaida if it is described as the movement driving global jihad rather than as an organisation. Theoretically, it is possible to trace a link between those suspected of the atrocity and bin Laden. The Moroccan arrested immediately after the bombings, Jamal Zougam, ran a phone shop in Madrid that allegedly supplied the mobile phones used in the attacks. He is thought to have associations with a Syrian, Abu Dahdah, in custody in Spain since 2001 and suspected of leading an al-Qaida cell there.
In turn, both men have been linked with the Moroccan extremists behind last May's attacks in Casablanca. Captured bombers interrogated by the Moroccan security services have apparently revealed connections with al-Zarqawi and to the Ansar al-Islam organisation he reputedly leads. Al-Zarqawi's close links to bin Laden and al-Zawahiri are well established.
But al-Qaida can no longer be described as a single organisation. Rather it is a motivational and inspirational movement for Islamists in dozens of countries.
In other words, they draw inspiration from bin Laden, but nothing more. That diffusion leaves such groups harder to monitor and makes the nature and locations of their attacks difficult to predict.
It also leaves huge anomalies in the information flow. Some claims made by intelligence experts pointed to co-operation between ETA and Islamist groups. Anyone with more than a cursory interest in the subject would dismiss the notion that a secular and Marxist group would align itself with Muslim fundamentalists. Yet, this unlikely alliance was given credence by more than one supposed expert from reputable institutes.
The latest edition of Newsweek also reported another extraordinary piece of intelligence: "Some Irish bomb-making experts were traced to Afghanistan, where they were working with al-Qaida before 9-11, according to two US government sources who saw intelligence reports in that connection," the article said.
Tommy McKearney, a former hunger-striker and an authority on republican paramilitarism, expressed incredulity at such a link.
"It just does not make a lot of sense," he said.
McKearney refers in particular to the republicans' strong support base in the US. "That support base would not have been terribly impressed with contact with al-Qaida, even prior to September 11. And from al-Qaida's perspective it would have left it vulnerable to penetration by British and American intelligence."
In the aftermath of Madrid, Europe is bracing itself against further attacks. EU interior ministers met last Friday but were unwilling to contemplate setting up a European version of the CIA. They want to instead improve co-ordination and exchange of counter-terrorist intelligence and security measures.
The "war on terror" will not be solved by enhanced security or by better intelligence-gathering alone. In the long term, solutions will have to be political rather than military. That boils down to some form of resolution being found in the tinderbox regions of the Middle East and central Asia.
For now, western Europe remains vulnerable to further such "spectaculars". Britain, America's closest ally, is thought to be the likeliest target. A German-based informant told his handlers that one of al-Zarqawi's cell was based at the London mosque where Zacarias Moussaouia (the so-called 17th hijacker) and shoe bomber Richard Reid both attended.
A truck bomb kills 21 outside a synagogue in Tunisia. The bomber is connected to Al-Qaida.
Over 200 people, among them many Australian tourists, are killed when two bombs explode in the Indonesian resort of Bali. The group behind the bombing, Jemaah Islamiah, has strong links to Al-Qaida
Two attacks in Kenya are aimed at Israeli tourists. Suicide bombers kill 13 at a Mobasa hotel and an Israeli commercial jet narrowly escapes being hit by a surface-to-air missile.
Multiple suicide bombings in Riyadh, Saudi Arabia, kill 24. A total of 43 people are killed in Morocco as a result of co-ordinated suicide bombings in Casablanca. Both attacks have been linked to Islamist groups with Al-Qaida connections.
The UN's top official in Iraq, the Brazilian democrat Sergio Vieira de Mello, is among the dead in an attack on the UN headquarters that kills 24 people.
Over 30 people are killed in a series of bombing attacks on the Red Cross headquarters and police stations in Baghdad.
Suicide bombers kill nearly 60 people in Turkey in bombs placed at synagogues, banks and at the British Consulate.
Almost 200 people are killed in suicide bombs during Shi'ite religious festivals in Karbala and Baghdad. Thirteen bombs placed on commuter trains in Madrid claim over 200 lives.
The founder and spiritual leader of Al-Qaida. Reputed to be in ill health, the Saudi multi-millionaire is believed to be in hiding in Afghanistan or Pakistan.
An Egyptian-born surgeon, he led the Egyptian Islamic Jihad, the group that was behind the assassination of Egyptian President Anwar Sadat in 1981. Now 52, he is Al-Qaida's second-in-command and Bin Laden's closest associate. Pakistan President Pervez Musharraf believe he had cornered al-Zawihiri during fierce battles with Al-Qaida sympathisers in western Pakistan last week. However, as fighting subsided, hopes of capturing him also faded.
Shadowy figure from Jordan, believed to be responsible for some of the worst atrocities in recent years. Now 37, little is known about his present whereabouts or appearance. Reputed to be the leader of Ansar al-Islam, a group based in Northern Iraq, and believed to have carried out the suicide bombings against Shi'ites in Baghdad and Karbala earlier this month.
Arrested by Spanish authorities in late 2001, he is said to have been the al-Qaida leader in Spain and may have met Mohammed Atta when he visited Spain not long before he led the September 11 attacks. A Syrian also known as Edim Barakhat Yarkas, he is also suspected of having links with Moroccan Islamic groups and with al-Zarqawi's Ansar al-Islam.