But whatever their preferred tactics for attaining power in predominantly Muslim countries — participation in free elections or deeds of violence — the various tendencies in political Islam offer their adherents a similar ideology. The historian Bernard Lewis has called this ideological program an “emotionally familiar basis for group identity, solidarity and exclusion; an acceptable basis for legitimacy and authority; an immediately intelligible formulation of principles for both a critique of the present and a program for the future.”

The proposals put forward in the most radical forms of this “critique of the present” are widespread in the Islamic world, and well-known outside it. They include hostility (in varying degrees) to political institutions that have been imported from the Western democracies, to the idea of an ideologically independent judiciary, the establishment of Western norms for human and civil rights, and, indeed, any rule of law other than one (sharia) that can be deduced from the Quran and the practices of the Prophet and the followers contemporary with him.

It should have come as no surprise, then, to learn from the National Post earlier this month that Islamist groups in the Middle East are urging Muslims in the Canadian diaspora to keep clear of the cultural forces and political institutions the groups oppose at home.

According to a recently declassified 2009 intelligence report assembled by Canadian government agencies and published in the Post, movements including the Muslim Brotherhood and the radical international organization Hizb-ut-Tahrir are telling Muslims here to create a “parallel society” and to live in “self-imposed isolation” from non-Muslim culture.

“Even if the use of violence is not outwardly expressed, the creation of isolated communities can spawn groups that are exclusivist and potentially open to messages in which violence is advocated,” the report said. “.... Isolationism can lead to conditions where extreme messages can incubate and eventually become the catalyst for violence. At a minimum, isolationism undermines a multicultural and democratic society.”

Some Post readers reacted to this story (in messages sent to the newspaper’s web site) by calling for the round-up and expulsion of Canadian Muslims. Such racist ranting is evil, and it also misses the point as far as Catholics are concerned.

Catholics, after all, are held to high standards of response by the Church’s teachings on tolerance, compassion and hospitality to strangers. If we are to remain faithful Catholics, we must then be worried, not only about our own safety — though the report certainly issues a clear warning about the potential danger of the situation — but also about the peace and security of our Muslim neighbours.

What should Catholics be doing for them to help them avoid the siren call of isolationism?

One task is to make sure Muslims, and all new Canadians, have full access to the rights and protections guaranteed by the Constitution, and to the opportunities of public life in a pluralistic society that is, on the whole, free and just. That means, among much else, language and other skills training for newcomers, and schooling in the legal system and Western political traditions that Canadians live with.

No amount of education will be effective, however, as long as morally serious young Muslims are fed only a corrupt, violent, intensely sexualized mass culture by the media and the Westerners among whom they live. Catholics must do better jobs as critics of this culture.

It’s worth remembering that recent perpetrators of Islamist terrorism in the West have not usually been the genuinely oppressed and poor, or Muslims who have chosen a path of isolation. Rather, they have tended to be middle-class young men who have tasted the poisonous, vulgar popular culture the Western media generates, and been profoundly repulsed by it. It is not our freedom the radical imams abroad despise. It is the deeply immoral popular culture — a culture of exploitation, excess and greed — that Westerners have created in the name of this freedom.

In their shared opposition to contemporary mass culture, serious Catholics and Muslims could possibly find common ground for fruitful dialogue. Be that as it may, Catholics are surely bound by the orthodox doctrine of the sanctity of the person to stand against what also offends and scandalizes devout Muslims so much: the unceasing gush of advertising, television, film, music, video games, books, pornographic videos and magazines, and other media that degrade the human being.

Taking on mass culture may well be Catholicism’s greatest new challenge of the 21st century.