The murders today in Paris are not a result of France’s failure to assimilate two generations of Muslim immigrants from its former colonies. They’re not about French military action against the Islamic State in the Middle East, or the American invasion of Iraq before that. They’re not part of some general wave of nihilistic violence in the economically depressed, socially atomized, morally hollow West—the Paris version of Newtown or Oslo. Least of all should they be “understood” as reactions to disrespect for religion on the part of irresponsible cartoonists.

They are only the latest blows delivered by an ideology that has sought to achieve power through terror for decades

A religion is not just a set of texts but the living beliefs and practices of its adherents. Islam today includes a substantial minority of believers who countenance, if they don’t actually carry out, a degree of violence in the application of their convictions that is currently unique. Charlie Hebdo had been nondenominational in its satire, sticking its finger into the sensitivities of Jews and Christians, too—but only Muslims responded with threats and acts of terrorism. For some believers, the violence serves a will to absolute power in the name of God, which is a form of totalitarianism called Islamism—politics as religion, religion as politics. “Allahu Akbar!” the killers shouted in the street outside Charlie Hebdo. They, at any rate, know what they’re about…

The cartoonists died for an idea. The killers are soldiers in a war against freedom of thought and speech, against tolerance, pluralism, and the right to offend—against everything decent in a democratic society.

A backdrop to the massacre in Paris on Wednesday by self-professed al Qaeda terrorists is that city officials have increasingly ceded control of heavily Muslim neighborhoods to Islamists, block by block.

France has Europe’s largest population of Muslims, some of whom talk openly of ruling the country one day and casting aside Western legal systems for harsh, Islam-based Shariah law.

“The situation is out of control, and it is not reversible,” said Soeren Kern, an analyst at the Gatestone Institute and author of annual reports on the “Islamization of France.”

“Islam is a permanent part of France now. It is not going away,” Mr. Kern said. “I think the future looks very bleak. The problem is a lot of these younger-generation Muslims are not integrating into French society. Although they are French citizens, they don’t really have a future in French society. They feel very alienated from France. This is why radical Islam is so attractive because it gives them a sense of meaning in their life.”

“The radicals are trying to exacerbate tensions that are already there,” said Jonathan Laurence, author of Integrating Islam: Political and Religious Challenges in Contemporary France. “They’re trying to drive a wedge between Muslims and the West.”…

Nile Gardiner, director of the Margaret Thatcher Center on Freedom at the conservative Heritage Foundation, also predicted greater cultural conflicts in Europe. “It’s inevitable there are going to be greater tensions now in France,” Gardiner said. “These attacks will elevate the issue of homegrown jihadists to the top of the political agenda.”

A similar discourse will take place all over Europe, as it has already in the United Kingdom, Gardiner said. “There’s a massive homegrown terrorist threat in the U.K. It’s also an issue in Belgium, Holland, Germany and across Western Europe,” he said. “This attack will up the stakes.”

Two polls conducted well before gunmen attacked the Paris offices of the satirical magazine Charlie Hebdo say a lot about the state of relations between France and its Muslim population, the largest in Europe.

An ICM Research poll last year found that 16% of the French had a “favorable” view of Islamic State. More than 27% of those ages 18 to 24 said they viewed the extremist movement favorably, while 22% of 25-to-34-year-olds reported a favorable view.

It was the highest favorable rate among three major European powerhouses. In contrast, only 2% of Germans and 7% of Britons reported a favorable view of the extremist movement.

French Muslims face not just social hurdles, but an officially-enshrined hostility to public displays of faith. Having fought its revolution, in part, to keep priests from meddling in state affairs, France has a passion for keeping church and state separate. “Secularism,” states france.fr, France’s official information website, “is a French invention.” Where the French cherish the neutrality of the public realm, free from any religious symbolism, mainstream Muslim culture embraces public declarations of religiosity through the veil or the call to prayer. France’s cherished codes of secularism clash with the public nature of the practice of Islam, a faith that in Muslim-majority countries is stamped on public life, from politics to laws to the wearing of beards and veils, or breaking for prayers in the middle of the work-day…

For many Muslims, it’s the official insistence on oneness and sameness that rankles. In 2008, a French court denied a Moroccan woman French citizenship on the grounds that her veil and her submissiveness to her husband were “assimilation defects.” Though the New York Times reported “almost unequivocal support for the ruling across the political spectrum,” one Muslim leader told the paper he worried the decision set a precedent for arbitrary decisions of what constitues a radical Muslim lifestyle. In 2010, the French Senate banned public wearing of face-coverings, including the Muslim face-veil, the niqab. And in 2013, the government launched what it called a Charter for Secularity in School, a set of guidelines on 15 key points of secularism to be posted in classrooms as an attempt to keep religion out of school. The then-government education minister, Vincent Peillon, insisted it was an attempt “to get everyone together,” but it had the opposite effect, with Muslim leaders claiming it stigmatized their community.

French Muslims are braced for a backlash after terrorists shouting Islamist slogans killed 12 people yesterday in Paris.

Community leaders are urging Muslims to stay vigilant and calm as fears of reprisals grow following the massacre at the offices of a satirical magazine. The leaders asked their community to avoid provoking other French people and join protests against the attack. They recommended that veiled women avoid going out alone.

“Panic is spreading,” said M’hammed Henniche, spokesman for UAM 93, an Islamic community group based in Seine-Saint-Denis, a working class Paris suburb. “More and more Muslim people are asking themselves, ‘What’s next?’”

The sophisticated, military-style strike Wednesday on a French newspaper known for satirizing Islam staggered a continent already seething with anti-immigrant sentiments in some quarters, feeding far-right nationalist parties like France’s National Front.

“This is a dangerous moment for European societies,” said Peter Neumann, director of the International Center for the Study of Radicalization at King’s College London. “With increasing radicalization among supporters of jihadist organizations and the white working class increasingly feeling disenfranchised and uncoupled from elites, things are coming to a head.”…

“This [French] secular atheism is an act of war in this context,” said Andrew Hussey, a Paris-based professor of postcolonial studies. Professor Hussey is the author of “The French Intifada,” which describes the tangled relations between France and its Muslims, still marked by colonialism and the Algerian war.

“Politically, the official left in France has been in denial of the conflict between France and the Arab world,” Professor Hussey said. “But the French in general sense it.”

The bodies haven’t been buried and the killers are on the loose, but that didn’t prevent anti-Islam politicians across Europe from seizing on yesterday’s massacre in Paris

“I wish my daughter will be free tomorrow to go around without a veil and without any fears,” Matteo Salvini, head of Italy’s anti-immigration Northern League, said on Twitter. Nigel Farage, leader of the U.K. Independence Party, spoke on LBC radio of a “Fifth Column” gnawing away at Britain and “a really rather gross policy of multi-culturalism.” Geert Wilders, head of the Freedom Party in the Netherlands, said it is time to “de-Islamize our country.”…

“One of the problems of Europe today is it is surrounded by regions, in North Africa, the Balkans, the Middle East where these dirty entanglements of corruption, crime and terrorism interact in such a potent way to destabilize the societies,” Louise Shelley, a professor at George Mason University in Virginia, told Bloomberg Television…

“In Europe right now there’s a tremendous amount of anti-immigration sentiment,” Daniel Benjamin, a former U.S. counter-terrorism official now with the Brookings Institution in Washington, said on Bloomberg Television. “The danger here is that we see ever greater confrontations, provocations and the like, and that will drive radicalization. That is a very difficult thing for the authorities to manage.”

In Islam, it is a grave sin to visually depict or in any way slander the Prophet Muhammad. Muslims are free to believe this, but why should such a prohibition be forced on nonbelievers? In the U.S., Mormons didn’t seek to impose the death penalty on those who wrote and produced “The Book of Mormon,” a satirical Broadway sendup of their faith. Islam, with 1,400 years of history and some 1.6 billion adherents, should be able to withstand a few cartoons by a French satirical magazine. But of course deadly responses to cartoons depicting Muhammad are nothing new in the age of jihad.

Moreover, despite what the Quran may teach, not all sins can be considered equal. The West must insist that Muslims, particularly members of the Muslim diaspora, answer this question: What is more offensive to a believer—the murder, torture, enslavement and acts of war and terrorism being committed today in the name of Muhammad, or the production of drawings and films and books designed to mock the extremists and their vision of what Muhammad represents?

To answer the late Gen. Malik, our soul in the West lies in our belief in freedom of conscience and freedom of expression. The freedom to express our concerns, the freedom to worship who we want, or not to worship at all—such freedoms are the soul of our civilization. And that is precisely where the Islamists have attacked us. Again.

How we respond to this attack is of great consequence.

The European Parliament complex in Brussels, where I happen to be sitting at the moment, is meant to be a monument to post-World War II continental ideals of peaceable integration, tolerance, free speech, and openness. All of these notions seem to be under attack at once, and what is striking to me, as a relatively frequent visitor to Europe over the past year, is that not many people—until a few hours ago, at least—seem to believe that their union, and their basic freedoms, are under threat…

I visited the Brussels Jewish Museum on Tuesday and got a glimpse of Europe’s future: Entering the museum is a bit like breaking into a prison. Barricades and unfriendly police outside; suspicious looks and CCTV surveillance; wanding and bag checks. All necessary, and, to be sure, Europe’s Jews, and its Jewish institutions, have been living in a semi-besieged manner for some time. But these measures will spread, by necessity…

The Charlie Hebdo massacre seems to be the most direct attack on Western ideals by jihadists yet. I’ve seen arguments advancing the idea that 9/11 represents the purest expression of Islamist rage at a specific Western idea— capitalism, in that case—but satire and the right to blaspheme are directly responsible for modernity. In the words of Simon Schama, “Irreverence is the lifeblood of freedom.”

The French president, Francois Hollande, said earlier today that, “No barbaric act will ever extinguish freedom of the press.” This statement is, as Claire Berlinski has pointed out, self-falsifying. This barbaric act, she notes, literally extinguished the press. The most recent iteration of the Islamist terror campaign in Europe has focused on Jews and cartoonists, but it will not end with Jews and cartoonists, unless it is comprehensively defeated.

France now faces an existential dilemma. By most independent estimates France now has a Muslim population of 6 million, or almost 10% of its 65 million people. If we assume that just 1% of this population are radicalized to the point of engaging in or providing support for terrorist activities, that is a pool of 60,000 individuals. We are not speaking of 60,000 potential bombers or shooters, but a support network that will allow a much smaller number of terrorists to blend into the broader population. In the “no-go” zones of France now effectively ruled by Muslim gangs, moreover, the terrorists can intimidate the Muslim population. France already has lost the capacity to police part of its territory, which means that it cannot conduct effective counter-terror operations

To put that number in context, the whole prison population of France is less than 70,000, of whom 60% are Muslims. It only takes a few dozen trained terrorists with an effective support network to bring ordinary life to a stop in a major city. France has had the toughest enforcement policy against radical Islam among the major European nations, as Daniel Pipes observes. But French security clearly has been overwhelmed. The use of assault rifles and (reportedly) a rocket launcher by highly-skilled gunmen in the center of Paris is a statement of contempt towards the authorities on the part of the terrorists.

The means by which France could defeat the terrorists are obvious: To compel the majority of French Muslims to turn against the terrorists, the French authorities would have to make them fear the French state more than they fear the terrorists. That is a nasty business involving large numbers of deportations, revocation of French citizenship, and other threats that inevitably would affect many individuals with no direct connection to terrorism. In the short term it would lead to more radicalization. The whole project of integration as an antidote to radicalism would go down the drain. The effort would be costly, but ultimately it would succeed: most French Muslims simply want to stay in France and earn a living.

There is no good outcome here, but the worst outcome would be the degeneration of France into a hostage state.