What is to be done? we wail. Most people's answers are as grandiose as they are unrealistic from eradicating world poverty, or resolving the Middle East conflict, to unseating Saddam Hussein. But, as in parts of Afghanistan, we are hitting the wrong targets. Osama bin Laden and his al-Qaeda group would not disappear even if all those goals were met.
For what al-Qaeda resembles is not so much a political terrorist grouping as a classic cult. Its members are not the dispossessed of the Gaza Strip, but middle-class, well-educated Muslims, many of whom have been to school or university in the West. Poverty was something they had not known until they chose to slum it in an Afghan cave.
Al-Qaeda fits all the official definitions of a cult. It indoctrinates its members; it forms a closed, totalitarian society; it has a self-appointed, messianic and charismatic leader; and it believes that the ends justify the means.
It also recruits exactly the same type of people. According to the Cult Information Centre, they tend to be intelligent, idealistic, well educated, economically advantaged and intellectually or spiritually curious. Just like Zacarias Moussaoui, for instance, a graduate with a master's certificate in international commerce, who was educated in France and Britain, and who the Americans believe was supposed to be the 20th hijacker.
Moussaoui, like all cult recruits, underwent a personality change after he came back from his training camp. He held beliefs that he had never held before: his family said he had been "indoctrinated."
These culturally rootless Muslims, alienated by the West, are peculiarly vulnerable to the lure of Osama bin Laden. They do not have to be passionate about the Palestinian cause or the presence of US bases in Saudi Arabia. Joining al-Qaeda fills a void in their psychological make-up: it gives them a sense of purpose, of security, and of identity.
The organization is expert in its psychology. First, like all cults, it teaches its members to subordinate their individuality to the goal of the group. Then the handbook al-Qaeda gives its terrorists contains incredibly detailed advice, and demands that they follow certain rituals: always a good way of inculcating a feeling of belonging to an exclusive tribe. All the hijackers, for instance, had shaved their body hair before getting on their aircraft.
Like other cults, such as Jim Jones's People's Temple, the Heaven's Gate sect or the Order of the Solar Temple, members are persuaded to give up their own lives for the promise of a paradise beyond. This technique was used a millennium ago by Hassan i Sabbah, a mystic, alchemist and master terrorist on whom bin Laden probably models himself. Hassan's Order of Assassins was made up of suicide killers with poisoned daggers who believed that their leader had the key to the gates of Heaven.
Interestingly, Hassan also allowed them to experience paradise on Earth before their missions. In his Iranian mountain hideout, he created an artificial paradise with fountains of milk and wine, spiced meat and, according to Marco Polo, "every delicious fruit and fragrant shrub that could be procured."
The assassins were not only fed and watered; they were also drugged with strong hashish and entertained by courtesans. A thousand years later, al-Qaeda's hijackers were encouraged to get drunk and visit prostitutes before they met their deaths.
So, if al-Qaeda needs to be treated more like the People's Temple than the IRA, what are the implications? Tony Blair's interview yesterday was more encouraging in this respect than his conference speech. For it is not so much world poverty that has to be eradicated but bin Laden himself.
Cults are famously difficult to disband, and some survive the death of their leader. But others implode once the messiah is gone. For instance, although 913 people died when Jim Jones persuaded them to drink cyanide-laced fruit juice in Guyana, 2,000 more of his adherents remained in California. Leaderless, they dissipated after his demise.
Maybe al-Qaeda could carry on. Maybe its upper ranks hold leaders as charismatic as bin Laden. But there is at least a chance that it does not. Alive, in a prison cell, bin Laden could continue to inspire and recruit followers. Mr Blair is right. Bin Laden is better off dead.