"Why would religious Muslims choose to come here, of all places," a city resident wondered as we discussed the tense debate over Islamic radicalism in the Netherlands. Within a few blocks of where we spoke, near the modern Opera House and the painter Rembrandt's historic home, tourists walked across quaint canal bridges into coffee shops where varieties of marijuana fill the menu, and gay couples stepped into Amsterdam's City Hall for wedding ceremonies that government officials have been conducting here for years without controversy.

Over the centuries, the Netherlands has come to see itself as the world's champion of tolerance, much as America considers itself the world headquarters of individual freedom. That proud self-image, however, has abruptly given way to an angst-filled identity crisis leaving the Dutch struggling to figure out how to deal with the very real risk of terrorism, wondering how to persuade Muslim immigrants to embrace their tradition of tolerance.

The Netherlands is a country torn between its efforts to preserve a cherished identity and the need to protect itself from murderous fanatics. That's an experience familiar to practically every democracy faced with a terrorist threat. But of all the places I've been, nowhere is the tension between security and tolerance as plainly visible as it is here. What the Dutch are discovering is that protecting their way of life may require undermining some of the very values they are trying to protect.

First to fall was the taboo against criticizing other cultures. The man to smash that taboo was the iconoclastic Pim Fortuyn, whose controversial statements against Islam and immigration ended when he was murdered (by an animal rights activist) in 2002. But his argument -- that the only way to protect Dutch tolerance was to be less tolerant -- was embraced by other politicians. Fortuyn, who was gay, was incensed when he heard Muslim clerics in Holland compare homosexuals to pigs and dogs. Tolerating this kind of speech from immigrants, said Fortuyn, would eventually lead to the destruction of the society the Dutch so carefully constructed.

While the Dutch are worried about the threat to their culture, they are terrified of what they believe is an impending terrorist attack. Polls show that it's the top concern of the population. Recent events have given the Dutch reason to worry. A few weeks ago, news reports here announced that the Dutch parliament building had been sealed and that there were police activities in several cities. Anxious moments later, word got around that police raids had netted seven people suspected of plotting terrorist strikes. Just days later, authorities in Baltimore stopped all traffic for almost two hours in a major tunnel under the Baltimore Harbor, responding to a tip about a possible attack that reportedly came from a man held in custody in the Netherlands.

One of those arrested in the Dutch raids was Samir Azzouz, a baby-faced 19-year-old who had already faced Dutch justice a few months earlier. Azzouz went to trial last spring after police allegedly found he had links to the Hofstad terror group. In his apartment they found explosives and maps of the Amsterdam airport, the parliament building and a nuclear power plant. But the progressive Dutch system, which does not even allow the media to reveal a convicted criminal's last name, ruled some of the evidence inadmissible and acquitted him of the terrorism charges, while convicting him of illegal arms possession.

The latest wave of arrests came after authorities said they found a video of Azzouz in which he said goodbye to his friends and family and, speaking in Arabic, referred to a certain "act" he was committing. Police claim he had been trying to buy explosives, and they believe he was planning a suicide bombing.

Many here expect an attack soon, perhaps to commemorate the anniversary of the day that changed everything. The day that so thoroughly traumatized Holland, not unlike America's 9/11, was Nov. 2, 2004, when a Muslim extremist killed and nearly decapitated the filmmaker Theo van Gogh in broad daylight on an Amsterdam street.

Van Gogh's own story captures the conflict over tolerance. The talented filmmaker made a career of stirring controversy in a country that has thrived on the unconventional. He had insulted just about every segment of society, and they put up with it. But when his film "Submission" offended some Muslims, extremists decided he, along with a number of politicians, must die. The killer, Mohammed Bouyeri, turned to van Gogh's mother after his conviction and said, "I do not feel your pain." He also vowed he would kill again if he were freed.

A telling commentary on the killing comes from Ayaan Hirsi Ali, a Somali-born member of the Dutch parliament who made the contentious movie with van Gogh and who describes herself as a "former Muslim." She has been sharply critical not only of Islam but also of the tolerance of Dutch society for certain aspects of Islamic culture. Hirsi Ali, whose life has been repeatedly threatened, believes the Dutch have allowed Muslims, particularly extremists, to keep traditions that simply should not be tolerated in the West -- such as their oppression of women. We can call it respect for another culture, she says, but they are human rights abuses. She sees that oppression as part of a subculture that calls for enforcing one's will, often through violence, in the name of an extreme interpretation of Islam.

One response to van Gogh's killing was a display of intolerance. Dutch youths took to the streets and burned Muslim schools and mosques. Most in Holland were horrified by the violence. The attacks have ended, but there is still a sense of confusion in the country. A year later, the atmosphere is the kind that helps extremists on all sides thrive. A number of politicians are living under police protection, even as they continue to receive death threats from Islamic radicals.

The immigration minister, Rita Verdonk, "Iron Rita," is spearheading a number of reforms that strike deep into the hearts of Dutch liberals. New immigrants, particularly from Muslim countries, are being required to take courses in Dutch language and society and they will have to pass a test to show their proficiency in Dutch culture in order to immigrate to the Netherlands. The latest proposal includes banning the burqa -- the head-to-toe cover worn by some Muslim women -- in public places. And a new plan would have foreigners expelled from the Netherlands for committing even minor crimes. Some politicians, like the flamboyant Geert Wilders with his bleached blond bouffant hair, call for a ban on immigrants from the Muslim world. Wilders, also facing death threats and living in hiding under police protection, says Islam is simply incompatible with democracy.

Defenders of immigrant rights and other liberal groups worry that a climate of discrimination is spreading through the deceptively placid and sedate Dutch landscape. Others say the Netherlands has always had a nasty streak hidden beneath the charming facade of quaint canals, tulip gardens and its everything-goes society.

The atmosphere, as they say, is ripe for abuse by extremist politicians. The threat, however, is not a political fabrication. The danger from extremism is real, and the presence of a radicalized core of Muslim extremists requires action. There is every reason to believe that some of the actions the government takes will create more resentments and, at least to some degree, undermine the freedoms and tolerance that the Dutch have valued as the core of their national identity.

The Dutch system, say people like Hirsi Ali, assumed all sides would practice tolerance. In a world in which the ways of one culture can prove so deeply offensive to others, and in which some of those who take offense express their objections through murder, those rules simply have to change.

Author's e-mail: fghitis@yahoo.com

Frida Ghitis, a frequent visitor to the Netherlands, is the author of "The End of Revolution: A Changing World in the Age of Live Television" (Algora Publishing).

Full alert: Police officers stood guard earlier this month outside the Dutch parliament buildings after seven suspects were arrested in a major anti-terrorism operation in three Dutch cities. Stop the hatred: A plea for change outside murdered filmmaker Theo van Gogh's funeral.