Europe's complex interplay with Islam appears to stand at a tipping-point, and the slaying of a Dutchman who made a movie critical of Islam could indicate one direction in which it is headed. "The Muslims say they're scared," said mourner Nicolette Toering. "No, we're scared."
Dutch authorities were investigating whether the chief suspect, a 26-year-old Dutch-Moroccan man detained shortly after the attack, acted alone out of rage or had links to wider extremist networks.
A five-page letter pinned to the body of Theo van Gogh, brutally murdered Tuesday as he was riding his bike down a busy boulevard in Amsterdam, called for Muslims to rise up against the "infidel enemies" in the West.
Other messages — later left at the sidewalk shrine where the 47-year-old filmmaker's throat was slashed — dripped with equal venom against radical Islam. "Enemies live among us," read one missive in a bed of flowers, votive candles and crosses.
The attack has underscored the hard political and social choices that European leaders face about Muslims and the wider Islamic world.
In December, European Union leaders will decide whether to overlook widespread public objections and move ahead with membership talks with Turkey, a Muslim nation of about 70 million people and a galloping birthrate that could push it past Germany's population in a generation.
European police agencies have sharply boosted cooperation against suspected Islamic terrorist groups following the March train bombings in Spain that killed 191 people. Washington's European allies in Iraq are reassessing their levels of military and commercial support following waves of attacks, kidnappings and beheadings blamed on Islamic militants.
EU officials last month signed the text of a proposed EU Constitution that still could face opposition from voters demanding a clear reference to Europe's Christian history.
But those big issues fade on the streets of many European centers. Here — even in places like tolerant Amsterdam — it's often expressed as a gnawing feeling that militant factions in Islamic immigrant communities are gaining ground and chipping away at values such as free speech and secular politics.
"There is a general feeling that a social collision is becoming inevitable," said Jan Rath, co-director of the Institute for Migration and Ethnic Studies at the University of Amsterdam. "People think it's been building for years and now finally coming to the surface."
The landmarks along the way included the 1989 death threat "fatwa," or religious edict, against British writer Salman Rushdie for alleged insults to Islam in "The Satanic Verses," the rise of neo-Fascist movements, the assassination of Dutch anti-immigrant politician Pim Fortuyn in 2002 and France's ongoing showdown with Muslims over a ban on headscarves and other religious apparel in schools.
"My impression is the European voices that say, `Everyone is equal, but we are more equal than Muslims,' are growing," Rath said.
The Netherlands offers a good vantage point to gauge changing attitudes toward Muslim communities across Europe — which have grown more than 100 percent in the past 15 years, according to U.N. reports. Some sources place the Muslim population as high as 13.5 million in Western Europe, or more than 2 percent of the population, in addition to more than 6 million native-born Muslims in the Balkans.
Unlike the French or Spanish, the Dutch long had little direct contact with Islam apart from a colonial presence in distant Indonesia that ended in 1949. Muslim immigrants began arriving following World War II as reconstruction labor — as they did in Germany and other countries.
The workers, mostly Turks, assimilated well into Dutch society. Moroccans and other North Africans began arriving in the 1970s and 1980s, when more lenient laws allowed men to bring in their families.
But the situation in Holland was getting tougher. Jobs were more scarce — especially for the Moroccan immigrant children — and some politicians began trying to connect the rising crime rate with the swelling Muslim community: now about 1 million in a country of 16 million people.
Last year, a parliament member, Geert Wilders, pressed for a five-year ban on immigration from Turkey and Morocco. Dutch anti-terrorist agents, meanwhile, have intensified probes into alleged radical recruitment among young Muslims.
Van Gogh — a distant relative of the famous 19th-century Dutch painter Vincent Van Gogh — often tested the boundaries of free expression by denouncing Muslims in the most graphic terms. His last work, "Submission," a joint project with Somali-born lawmaker Ayaan Hirsi Ali, attacked the treatment of women under Islam.
The filmmaker's fans were as passionate as his detractors.
"He was trying to warn us about the dangers of radical Islam," said teacher Geert Plas as he visited the site where Van Gogh was ambushed. "Now maybe we'll listen. To me this is not just a small event. It's part of the World Trade Center and Madrid. We must see this."
The letter pinned to the victim's body also threatened death to Hirsi Ali, who has gone into hiding, and predicted the downfall of the "infidel enemies of Islam" in Europe, America and the Netherlands.
"The jihad (holy war) has come to the Netherlands," parliament speaker Jozias van Aartsen said.
The memorials that piled up on the dark brick sidewalk often crossed the line from sympathy to seething recriminations. "This is the true face of Islam," said a handwritten message. A framed poem called "Imam" ends with a stanza: "If you want to improve the world, start with yourself and your faith."
A banner waved from a fence: "Theo rests his case."
Christian prayer cards, crosses and biblical passages sat amid the flowers — a rare religious outpouring in one of Europe's most secular states.
"This doesn't just say something about the Netherlands," said Baukje Prins, assistant professor of social philosophy at Holland's Groninjen University. "It is an example of how international relations have become polarized."
At a mosque near the murder site, Friday prayers were dominated by talk of the slaying — sprinkled with worry about a possible backlash.
"We are in danger," a Moroccan man told a group of friends sitting in a circle on a carpeted floor.
"No, no," another man said. "We cannot give in to fear. This is our home now."
Moulay Idrissi listened and shook his head.
"I'm afraid. I can't deny it," said Idrissi, who emigrated from Morocco in 1978. "I feel respect for Muslims is falling away in Europe. When people have no respect, anything can happen."
A few hours later, suspected arsonists set fire to a mosque in the central Dutch city of Utrecht, but no injuries were reported.
A 22-year-old student, Abdul Salam, said he tries to tell Christian friends that Muslims have been in Europe since the Moors crossed into Spain in the 8th century.
"So I don't know what to think when people say I don't belong here because I'm Muslim," he said. "I was born here. I don't even speak Arabic. I am European. That's what I feel. That's what I am."
But Salam represents just one side of an internal struggle within Muslim communities in Europe, said Akbar Ahmed, a professor of Islamic studies at American University in Washington.
"Right now the West sees all Islam as a kind of monolith and wipes away all nuances," said Ahmed. "Some want to draw boundaries around Islam in Europe. Other Muslims want to deal with non-Muslims in a broad and tolerant way. It's not new to Islam. It's just new to Europe."