CITIZENS.(The Talk of the Town)

In a world amply populated with angry young Muslims, it is a question of some interest why a small number choose to become suicide bombers. President Bush addresses the matter in starkly religious language, consigning it to an eternal contest between good and evil. American scholars have begun to attack the problem with scientific method; Robert Pape, of the University of Chicago, for example, recently mustered data to argue that suicide attacks are a rational means by which the weak can humble the strong. To this potpourri of hypotheses can now be added a compelling work by anonymous bureaucrats in Great Britain, under the oddly redundant title "Report of the Official Account of the Bombings in London on 7th July 2005."

On that summer morning, three young Muslim men blew themselves up on Underground cars, and a fourth immolated himself on a double-decker bus; fifty-two people died, and several hundred suffered injuries. The most striking aspect of the inquiry into the attacks, which was published earlier this month, is the extent to which it plumbs the suicide bombers' motivations.

The four men depicted in the report are in some respects unfathomable. When Shehzad Tanweer, a talented athlete who was twenty-two years old, bought snacks at a highway convenience store four hours before his death, he haggled over the change. Hasib Hussain, who was eighteen, strode into a McDonald's just half an hour before he killed himself and thirteen others. When the four men took leave of one another at King's Cross station, they hugged, and they appeared, the report says, "happy, even euphoric." To the credit of the British investigators, however, they were not satisfied merely to observe that the bombers had enrolled in an appealing death cult. They wanted to know how the men were radicalized on British soil--not to excuse them but to aid a strategy of prevention.

Three of the bombers were British citizens, and the report makes plain that this was not just a technical matter of passports or residence status. They were far from destitute; born to Pakistani immigrants, they attended secular state schools and received government and family support throughout their short lives. (The fourth bomber was a Jamaican immigrant who converted to Islam, and whose life was more troubled and erratic.) The ringleader, Mohammad Sidique Khan, even worked for a time at a British welfare agency; later, he was a well-liked teacher's aide. And yet citizenship failed to compete with the lure of enlistment in an imagined jihadi militia. Khan lost his job just before he began to plan the London bombings. In a video statement left for posthumous broadcast, he emphasized with every pronoun he chose that he had abandoned British identity for service in an enemy army: "Your democratically elected governments continuously perpetuate atrocities against my people all over the world. And your support of them makes you directly responsible."

The report concludes that there is no consistent profile that could be used to help identify who might be vulnerable to such radicalization, and yet the biographies do show in some detail how the making of an Al Qaeda-inspired suicide bomber is an idiosyncratic narrative of push and pull. Alienation from citizenship or family and a loss of faith in secular opportunity create a pool of potential volunteers; preachers, recruiters, and Al Qaeda leaders take it from there. The British parliament's main intelligence-oversight committee, in a separate report, admits that Britain has failed to consider adequately how it might reduce the number of potential recruits: "We remain concerned that across the ...