AMSTERDAM’S Linnaeusstraat is a bleak place to die. Lined with budget stores and overshadowed by a railway bridge, it is largely populated by Muslim immigrants. On November 3 last year, the film-maker Theo van Gogh halted his bike in the cycle lane. The anti-clerical van Gogh had made many films criticising Christianity and Judaism, as well as Submission, an indictment of Islam’s treatment of women, based on the experiences of Ayaan Hirsi Ali, the Dutch-Somali MP.

Muhammad Bouyeri, a young Moroccan, came alongside Van Gogh. He shot him in the side, propelling van Gogh to the ground. The victim managed to get up, lurching through the traffic. Bouyeri tracked his victim, shooting him twice more before trying to cut his head off with a butcher’s knife. He then rammed a smaller knife into Van Gogh’s chest, with a letter threatening two Dutch politicians slipped over the blade.

Bouyeri ran into a park, where he was captured. He had a poem in his robes, which included the line: “The knights of death are at your heels.” He belonged to a small Islamist radical cell conspiring to blow up Schiphol airport. He is now serving a life sentence for murder. The Dutch reaction to the murder has been ferocious, up to and including banning wearing of the burka.

Islamist terrorism is not a phantom product of our nightmares and neuroses, but a real and present danger in the world. There have been devastating attacks in Kenya and Tanzania, 9/11, Bali, at Atocha station in Madrid and the July suicide bombings in London, commemorated this week. At present, Australia is on high alert.

Osama bin Laden, the inciting intelligence behind many of these atrocities, certainly believed in a “clash of civilisations”, as he called it. His justification for 9/11 was a bizarre fusion of finance and theology. The twin towers reminded him of the moon idol Hubal, worshipped by pagan Meccans until Muhammad demolished all lesser gods. But bin Laden’s stream of consciousness also included totting up the financial cost of 9/11 to the US, in terms of disrupted financial markets, lost employment and reconstruction, arriving at a net loss of $1 trillion for the modest investment of $500,000 that these attacks are thought to have involved.

But bin Laden has competition in the stakes for the world’s most wanted terrorist. His erstwhile Jordanian protégé, Abu Musab al-Zarqawi, established his credentials as a murderer by cutting off the head of the US businessman Nicholas Berg, graduating to bomb attacks in Iraq that claim 60 lives a day. Perhaps al-Qaeda’s Ayman al-Zawahiri, who has expressed “concern” about the killing of Iraqi Muslims, may get to al-Zarqawi before American special forces do. Big egos are at play.

President Bush, Tony Blair and John Howard, the Australian Prime Minister, have been commendably unflinching in their determination to eradicate the pestilence of Islamist terrorism. Other governments are trying a different tack, which smacks of appeasement. Last week in Madrid, I attended a “Dialogue between Cultures and Religion”, organised by a foundation with links to Spain’s ruling socialists. Here, talk of “dialogue” between faiths effortlessly mutated into the separate notion, promoted by Spain and Turkey, of “an alliance of civilisations” spanning the Mediterranean world. Countries can ally; civilisations generally don’t. A banquet in the government quarter elicited the intelligence, from a Moroccan diplomat, that not only was “Europe” morally superior to a US symbolised by Bush’s Texas, but that a distinctive “fusion” culture was emerging in the Mediterranean, “different ” from that of northern Europe. One doubts whether the Italians feel that way.

The conference opened with protestations of goodwill from Mohammad Khatami, Iran’s former president, delivered by an ambassador who was not among those recalled for failing to reflect the crazed views of President Mahmoud Ahmadinejad. Felipe González, the former Spanish premier, chose to overlook Ahmadinejad’s rant, preferring to contest the notion of a “clash of civilisations”, as if this were US policy.

At least Miguel Ángel Moratinos, the Spanish Foreign Minister, managed condemnation of an elliptical sort. He has been a prime mover of the claim that you cannot “fight evil with evil”, a formula begging many questions about moral equivalences. He favours marginalising extremists through a dialogue with Muslim “moderates”. These included Dr Tariq Ramadan, an Egyptian intellectual, who is on an FBI watch list and banned from France, but welcome in Spain.

Discussion of religion and politics took the form of a “dialogue” between aggressive secularists — on this occasion Spanish socialists with memories of “national Catholicism” under Franco — who averred, against all the evidence, that “religion” will “inevitably” fade away, and those who think it is an essential and vital force in the modern world. This was a dialogue of the deaf, because Western liberals have become totally unmusical on the subject of religion, which they nevertheless combat with an evangelical fervour.

I mentioned the Chief Rabbi Jonathan Sacks’s striking metaphor of Britain needing the ethos of a country house rather than a Holiday Inn to overcome the divisive effects of multiculturalism. An evangelical Christian lady ran with this idea, suggesting — presumably not to the Muslims present — that we all needed to be buying drinks for each other in the hotel bar rather than skulking in isolated rooms.

The fate of a Dutch film director hacked down by a maniac seemed remote from the Madrid junket. After all, that was northern Europe. Actually, the conference was a few minutes’ drive from the station where 200 people were killed by a Moroccan terrorist network. Dialogues between civilisations, Christian, Islamic or other, are fine, but a constant part of this must be the grim reality that visited Van Gogh on a cold northern street, an event depressingly indicative of the ethnic and religious complexity of Europe. We cannot wish away the clash of civilisations.

Michael Burleigh is author of Earthly Powers. Religion and Politics in Europe from the French Revolution to the Great War

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