France is likely to be the first European country to experience societal upheaval and a radical reordering as a result of immigration. There are signs such an upheaval is already underway.

On Thursday evening, France was once again the target of a terrorist attack. A commercial truck ploughed into revelers gathered in Nice to celebrate France’s national holiday, Bastille Day, while the driver, and possibly other accomplices, shot into the crowd as they drove. Details are still emerging, but as of this writing 77 people are feared dead and hundreds more are injured. French police fired on the truck, killing the driver.

Images of the attack posted to social media Thursday night showed bodies strewn in the streets, scores of people running for safety along the waterfront, and the attackers’ truck riddled with bullet holes.

As France absorbs the shock of another mass-casualty attack, something dangerous is stirring in the heart of the republic. France’s chief of intelligence, Patrick Calvar, warned members of a French parliamentary commission earlier this week that if another terror attack were to happen in France, or something akin to the New Year’s Eve mass sexual assaults in Germany, it could spark a “civil war.” Calvar expressed concern about a populist backlash that would lead to a “confrontation” between ultra-right groups, such as Bloc Identitaire, and the rest of the country—especially Arab and North African immigrants.

With the revelation this week, due to a botched cover-up, that far more women were sexually assaulted in Germany on New Year’s Eve than was previously known, and the latest tragic terrorist attack in Nice, the possibility of major destabilization in the country seems all the more likely.

But a revolt in France wouldn’t just be a reaction to outside events. It would also come from deep within France’s unique culture and history. Indeed, France is likely to be the first European country to experience societal upheaval and a radical reordering as a result of immigration. There are signs such an upheaval is already underway.

The Rise of the Worldwide National Front

In the wake of high-profile terrorist attacks over the past year and a half, coupled with the ongoing migrant crisis, French voters are looking to the National Front for relief. The far-right nationalist party led by Marine Le Pen, who speaks openly about the dangers of terrorism, has called for leaving the European Union and the Euro.

The party’s rhetoric is unabashedly nationalistic, although it doesn’t approach the radicalism of the ultra-right. In recent polling, 28 percent of French voters said they would vote for Le Pen, twice as many as for current Socialist President François Hollande. Nicolas Sarkozy, former president and expected Republican candidate, comes in at 21 percent, making it likely Le Pen could reach the second round of voting in next year’s elections.

The rise of the National Front is part of a trend of rising populism and nationalism across the West. In Britain, the decision to leave the European Union has been called protectionist and racist against migrants. Germany has already seen roving bands of far-right vigilantes and attacks on migrant centers. Austria is re-doing its presidential election after the far-right candidate lost by only a couple thousand votes amid accusations of voter fraud. In the United States, the Trump movement has heavy overtones of American nationalism, with his supporters calling for an end to free trade and a drastic reduction of immigration.

Some of this is the natural backlash against the efforts of Western ruling elites to make everyone citizens of the world. Although certainly some Brexiteers voted “leave” solely based on quasi-racist views on immigration, it also had a lot to do with taking back their national sovereignty. They want Britain, not Brussels, to decide how many migrants they will take in or what kind of trade deals they will adopt. The migrant crisis was just the issue that brought things to a head.

France Has a Singularly Strong National Identity

France is experiencing a similar reaction. However, its swing toward nationalism is unique because of its history—and therefore more likely to succeed. If the migrant crisis were the tipping point for Brexit, it would be the raison d’être for a French “civil war.” If France decides to elect Le Pen and leave the EU, causing a major rift in the country, it would be due, in part, to France’s sense of national identity. That identity is more closely linked with France’s language, heritage, and culture than in most other Western countries. A revolt would come from deep within the country’s belly.

Ever since the French Revolution, the country has supposedly been based on the idea that all peoples can approach the apparatus of the state equally, regardless of nationality or ethnicity. This was supposed to solve the blood-and-soil nationalism that plagued the continent. In practice, however, it hasn’t worked. The supremacy of the French language makes this clear. Beginning in the first years after the revolution, the state aggressively purged French dialects, declaring they were languages of treason. This was followed by a language standardization effort unparalleled in history.

Today, France has strict protectionist laws about language and culture. All advertisements and public announcements must be in French, as must all official communications in the workplace, even from subsidiaries of foreign companies. The labels on all products must include French, and schools where French isn’t the primary language of instruction are ineligible for government funding. France also strictly regulates the percentage of broadcast television content that can be non-French.

As with language, so too with ethnicity. France has only begrudgingly accepted its North African population, which began to immigrate after World War II for temporary job opportunities. It was assumed these immigrants would leave after a few years. When this didn’t happen, and North African workers began bringing their families over, France struggled to make peace with the idea of their former colonial subjects becoming French citizens.

A Commitment to Unity Under Attack

A question often posed in discussions of French culture is “Qu’est-ce qu’un français?” (What is a French person). The answer for many in France—even if it’s often denied by the liberal elites—is someone who speaks French, whose heritage is Anglo-Saxon, and whose religion (even if just nominally) is Catholic. One can see this expressed in Le Pen’s surge in popularity. While America is often thought of as a country of immigrants, the French state is equivalent to French patrimony.

There’s only so much they’ll let their culture be watered down, whether from North African immigrants or the American cheeseburger—and there’s only so long they’ll allow themselves to be governed by non-French entities like the EU. French nationalists in particular certainly won’t put up with the migrant crisis much longer if it continues to be linked to terrorism and sexual assaults.

All European countries have this kind of nationalism in them. But France’s unique history of trying to force conformity makes it likely that a populist uprising will happen there first. It makes a populist revolt more possible and the chances of rancorous division in the country more immediate.

Is there going to be a civil war? Probably not. But after the horrifying scene in Nice, France could lurch so far to the right that it tears at the fabric of the country, triggers mass riots, and leads to a messy exit from the EU. If that happens, other European countries will not be far behind.