In this former industrial town north of London, a small group of young Britons whose parents emigrated from Pakistan after World War II have turned against their families' new home. They say they would like to see Prime Minister Tony Blair dead or deposed and an Islamic flag hanging outside No. 10 Downing St.
They swear allegiance to Osama bin Laden and his goal of toppling Western democracies to establish an Islamic superstate under Shariah law, like Afghanistan under the Taliban. They call the Sept. 11 hijackers the "Magnificent 19" and regard the train bombings in Madrid, Spain, as a clever way to drive a wedge into Europe.
On Thursday evening, at a tennis center community hall in Slough, west of London, their leader, Sheik Omar Bakri Mohammad, spoke of his loyalty to bin Laden. If Europe fails to heed bin Laden's offer of a truce -- provided that all foreign troops be withdrawn from Iraq in three months -- Muslims will no longer be restrained from attacking the Western countries that host them, Mohammad said.
"All Muslims of the West will be obliged," he said, to "become his sword" in a new battle. Europeans should take heed, he added, saying, "It is foolish to fight people who want death -- that is what they are looking for."
On working-class streets of old industrial cities like Crawley, Luton, Birmingham and Manchester, and in the Arab enclaves of Germany, France, Switzerland and other parts of Europe, intelligence officials say a fervor for militancy is intensifying and becoming more open.
In Hamburg, Mustafa Yoldas, the director of the Council of Islamic Communities, saw a correlation to the discord in Iraq.
"This is a very dangerous situation at the moment," Yoldas said. "My impression is that Muslims have become more and more angry against the United States."
Hundreds of young Muslim men are answering the call of extremists into groups affiliated or aligned with al-Qaeda, intelligence and counterterrorism officials in the region say.
Even more worrying, said a senior British counterterrorism official, is that the level of "chatter" -- communications among suspected terrorist figures and their supporters -- has markedly increased since bin Laden's warning to Europe this month. The spike in chatter has given rise to acute worries that planning is advanced toward another strike in Europe.
"Iraq dramatically strengthened their recruitment efforts," one counterterrorism official said. He added that some mosques now display photos of US soldiers fighting in Iraq alongside bloody scenes of bombed-out Iraqi neighborhoods. Detecting actual recruitments is almost impossible, the official said, because it is typically done face to face.
And recruitment is paired with a compelling new strategy to bring the fight to Europe.
Members of al-Qaeda have "proven themselves to be extremely opportunistic, and they have decided to try to split the Western alliance," the official continued. "They are focusing their energies on attacking the big countries" -- the US, Britain and Spain -- so as to "scare" the smaller states.
Some Muslim recruits are going to Iraq, counterterrorism officials in Europe say, but more are remaining home, possibly joining cells that could help with terror logistics or begin operations like the one that came to notice when the British police seized 500kg of ammonium nitrate, a key bomb ingredient, in late March, and arrested nine Pakistani-Britons, five of whom have been charged with trying to build a terrorist bomb.
Stoking that anger are some of the same Islamic clerics who preached violence and martyrdom before the Sept. 11, 2001, attacks.
On Friday, Abu Hamza, the cleric accused of tutoring Richard Reid before he tried to blow up a Paris-to-Miami jetliner with explosives hidden in his shoes, urged a crowd of 200 outside his former Finsbury Park mosque to embrace death and the "culture of martyrdom."
Though British Home Secretary (interior minister) David Blunkett has sought to strip Hamza of his British citizenship and deport him, the legal battle has dragged on for years while Hamza keeps calling down the wrath of God.
Despite tougher anti-terrorism laws, the police, prosecutors and intelligence chiefs across Europe say they are struggling to contain the openly seditious speech of Islamic extremists, some of whom, they say, have been inciting young men to suicidal violence since the 1990s.
One chapter in Mohammad's lectures these days is "The Psyche of Muslims for Suicide Bombing."
The authorities say that laws to protect religious expression and civil liberties have the result of limiting what they can do to stop hateful speech. In the case of foreigners, they say they often are left to seek deportation, a lengthy and uncertain process and subject to legal appeals, during which the suspect can keep inciting attacks.
That leaves the authorities to resort to less effective means, such as mouse-trapping Islamic radicals with immigration violations in hopes of making a deportation case stick.
"In many countries, the laws are liberal and it's not easy," an official said.
While some clerics, like Abu Qatada -- said to be the spiritual counselor of Mohamed Atta, who led the Sept. 11 hijacking team -- remain in prison in Britain without charge, others like Mohammad, leader of a movement called Al Muhajiroun, carry on a robust ideological campaign.
Mainstream Muslims are outraged by the situation, saying the actions of a few are causing their communities to be singled out for surveillance and making the larger, non-Muslim population distrustful of them.
Muhammad Sulaiman, a stalwart of the mainstream Central Mosque here, was penniless when he arrived from the Kashmiri frontier of Pakistan in 1956. He raised money to build the Central Mosque and now leads a campaign to ban Al Muhajiroun radicals from the city's 10 mosques.
"This is show-off business," he says in accented English. "I don't want these kids in my mosque."