British police have made a dramatic breakthrough in the hunt for the London bombers, but the discovery that the suspects were young Britons, not hardened Al Qaeda foreigners, has heightened jitters and raised questions about how Britain prosecutes the war on terror.
Police now say that the 7/7 attacks could be the first suicide bombings ever in Western Europe. They believe the perpetrators were second-generation Britons of Pakistani descent aged 18 to 30, possibly acting with some outside help.
If substantiated, the vigorous and rapid police work would give credence to the idea that Britain has more to fear from an "enemy within" than from shadowy Al Qaeda cells abroad.
Experts say the challenge for authorities now will be to combat terrorism by bolstering mainstream Muslim society to ensure no further defections to the fanatical jihadi camp. This effort, they say, should focus as much on acts of civic integration and inclusion as on the security-led war on terror that has alienated many.
Prime Minister Tony Blair hinted as much Wednesday when he told Parliament that "security measures alone are not going to deal with this." Still, he noted that the government would press ahead with legislation cracking down on those who incite hatred and violence, while seeking to banish foreigners who whip up terrorist fervor.
But he emphasized that no less important were initiatives to help the stricken Muslim community isolate the extremists in its midst. Success, he suggested, would come from confronting the "extreme and evil ideology" behind the attacks. And "this evil within the Muslim community," he argued, can only be defeated by the community itself. To that end, he urged the moderate voice of Islam to drown out the voluble extremism amplified globally.
It's no secret that Britain has for years provided fertile soil for Islamic hard-liners. Some radical imams freely deliver Friday sermons filled with invective against Britain and "infidels."
One man linked to a south London mosque, Richard Reid, was convicted of trying to blow up an aircraft soon after 9/11. Two other Britons carried out suicide bombings in Tel Aviv two years ago. Police have arrested dozens of others suspected of preparing terror spectaculars. Pakistan said Wednesday it helped Britain thwart an attack before the May general election.
But despite several foiled attacks, last Thursday's bombers passed under the radar. Police have pieced together a partial narrative from the attacks, when four rush-hour explosion bombs, three on the Tube and one on a bus, killed more than 50 and injured 700.
The vital tip-off came from one of the suspect's own families, who called police when he failed to return home last Thursday. On Tuesday, police raided a series of homes in Leeds, some 200 miles north of London, where they found explosives and arrested a man believed to be related to the suspects. They also impounded a vehicle at Luton railway station, 40 miles north of London, and found more bomb-making materials.
They now say three of the suspects drove from Leeds to Luton early on Thursday, where they met a fourth suspect. Closed-circuit television footage shows the four arriving at King's Cross station shortly before 8:30 a.m., looking calm and carrying large rucksacks. The three underground bombings all happened within 1 minute of each other on direct subway lines out of King's Cross. The fourth tore apart a bus nearly an hour later, less than a mile from the station. Police say they have forensic evidence and personal documents pinning down the alleged culprits.
Though the four are now believed to be dead, copycat acts are feared. "If four or five guys dreamed this up, it's likely that others are dreaming it up, too," says Simon Sole, a former intelligence officer and expert in Islamic radicalism.
Analysts say the likelihood that the quartet were Britons dramatically alters the cultural context of the attacks.
"It would have been much more palatable if they had been radical bombers who came to the UK for the operation," says Bob Ayers, a security expert at London's Chatham House think tank and a former counterintelligence officer. "Because they were British nationals born in UK, they were striking against their own society. That's traumatic to digest."
Suddenly, great attention has been given to the motives of the quartet, dubbed the "suicide bombers of suburbia" by the British press.
Friends and relatives of the suspects have painted a picture of ordinary young men, one a sports-loving student, another a teacher with a young family, a third a loner who discovered religion.
The area they come from near Leeds is not upscale but not destitute. These people "lead humdrum lives and they want adventure and there's a legitimizing framework for them in the form of radical teachers," says Mr. Sole, who serves as managing director for London's Executive Analysis consultancy.
British officials have made strong alliances with moderate Muslims to appease the community and get closer to its radical fringes. But Muslim leaders, who have condemned the attacks and vowed to root out radicalism, say the government could help by recognizing the disenchantment of a community generally blighted by unemployment and social exclusion, and disillusioned by Britain's attachment to the US strategy in the war on terror.
Though they stress this is no excuse for terrorism, they feel that more effort should be spent building bridges at home rather than pursuing campaigns like the Iraq war.
"We need to really look at some of the causes which could feed into these feelings, the disadvantages and discriminations," says Mohammed Anwar, an expert in race relations at Warwick University. "The government and the institutions of our society could help in this."
About 100 race attacks have already been reported on Muslim targets in less than a week.
"We need to be careful not to label the whole community," says Mr. Anwar.