The savage acts of terrorism in Oslo last week shocked people of goodwill and conscience around the world. The deadliness of the attacks — 77 people, many of them youths, were killed during a calculated, merciless shooting rampage and a bombing near the government’s headquarters — and the cruelty behind them make it difficult to set aside emotion and consider their significance. Yet when studying the apparent motivations, as expressed by confessed perpetrator Anders Behring Breivik, a crucial point emerges.

Europe and the United States have been no strangers to violence motivated by anti-
Islamic sentiments over the past decade. Muslims have been assaulted and killed, their mosques and institutions damaged and destroyed. Yet the majority of the attacks have fallen into only a few categories:

●Hate crimes typically motivated by culturally or religiously based anti-Islamic prejudice.

●Acts of retaliatory or reactionary violence.

●Violence by white supremacists, who usually hate the race and religion of the majority of Muslims.

For example, this month Texas executed a white supremacist, Mark Anthony Stroman, who in 2001 targeted and fatally shot convenience store clerks of perceived Middle Eastern appearance in “retaliation” for the Sept. 11 attacks.

The attacks in Norway seem to stem from a different source. They are the first to emerge from a relatively new, specifically anti-Islamic ideology that moves beyond religious or racial prejudices to incorporate anti-Islamic sentiment as the focal point of a larger worldview.

Growing numbers of people in Europe and the United States subscribe to this belief system; in some instances it borders on hysteria. Adherents of this ideological Islamophobia view Islam as an existential threat to the world, especially to the “West.”

Moreover, they believe that leaders and governments in the Western world are consciously or unconsciously collaborating to allow Islam to “infiltrate” and eventually conquer democratic societies.

Left-wing “multiculturalist” sentiments tear down traditional European culture, they argue, allowing Muslim immigrants to replace it with “their own” culture and values. The result, they claim, will be the demographic, cultural and, eventually, political suicide of the West — unless action is taken to stop it.

These ideas are no longer geographically isolated. The Oslo perpetrator in his manifesto quoted extensively from the writings of European and American bloggers — including Robert Spencer and Pamela Geller — who promote a conspiratorial anti-Muslim agenda under the pretext of fighting radical Islam. Because of the reach of the Internet, these ideas float freely across borders and are reinforced by like-minded bigots.

This belief system goes far beyond anti-Islamic prejudice based on simple religious or racial grounds. In a sense, it parallels the creation of an ideological — and far more deadly — form of anti-Semitism in the late 19th and early 20th centuries on the backs of the previously dominant cultural and religious forms of anti-Semitism.

The presence of this new ideological form of anti-Islamism is clear in the Norway attacks. The perpetrator, though motivated by anti-Islamic sentiments, did not attack or kill Muslims. Rather, he reserved his extreme actions for those “traitors” whom he believed to be collaborating with and allowing Muslims to take over Norway (and Europe). He chose targets related to the Labour Party, the alleged “multi-cultural Marxists” who dominated his thoughts.

Breivik’s acts are so far the only major incidents like this. Perhaps they will remain unique. His thinking, however, is certainly not. Thanks to his carefully sourced manifesto, we can identify many of his intellectual influences, and they are prominent on both sides of the Atlantic. And many people hold views similar to Breivik’s. In the United States, we have seen frequent manifestations of this ideology, including the eager promotion by anti-Islamic zealots of a growing conspiracy theory about “creeping Sharia law.”

One bizarre twist to Breivik’s warped worldview was his pro-Zionism — his strongly expressed support for the state of Israel. It is a reminder that we must always be wary of those whose love for the Jewish people is born out of hatred of Muslims or Arabs.

The obvious danger to Americans and Europeans is that as this movement grows and solidifies, more people may become motivated to violence by this hateful ideology.

In America, the polarization, vitriol and fear engendered by anti-Islamic activists must be replaced by reasoned and civil debate. We must rally the voices of reason to overcome the voices of intolerance before it is too late.

The writer is national director of the Anti-Defamation League.