For many politicians and pundits in France and the United States, last month’s terrorist attacks in Paris marked the latest spasm in the burgeoning “clash of civilizations” between West and East, reason and religion, secularism and Islamism. This particular worldview often spans political differences: While Republican Sen. Marco Rubio declares there to be “no middle ground” in this “clash of civilizations,” the Socialist Prime Minister of France, Manuel Valls, warns against “la guerre des civilisations.”

Of course, other political and public figures have dismissed—and rightly so—this description as a caricature of the deep sources of recent events. To portray the attacks as what happens when religious and ideological worlds collide ignores, among other things, the depth and diversity of Islam. But the shockwaves rippling across France are nevertheless the work of a different sort of clash, one that might elicit raised eyebrows rather than nodding heads.

Rather than a conflict between civilizations, France confronts one between generations. It is one that, admittedly, is more prosaic, even humdrum than one of entire civilizations barreling into one another. But for that very reason it needs to be taken seriously, for it speaks to the stubborn character of the problem.

Olivier Roy, the noted French scholar of Islam, recently suggested that the hundreds of French youths who have joined the Islamic State are not at all religious zealots. Instead, they are little more than opportunists who are intent on slaking their thirst for violence. Tellingly, not only have French-born offspring of North African immigrants to France proved vulnerable to the siren call of revolutionary violence and brutality. So, too, has a small but significant number of so-called français des souches: French youths of neither North African nor Muslim background who find a grim and appalling form of self-expression in the black uniforms and blacker brutality of the Islamic State.

Twenty years ago, such youths rallied to radical Islamic movements in Chechnya and Bosnia, or joined the Groupe Islamique Armée in Algeria or the various al-Qaeda affiliates. Today, they are flocking to the Islamic State, as ignorant of Islamic theology as they are indifferent to the different historical and social traits that have defined these various radical movements. In effect, what we are witnessing is not the radicalization of Islam, but the Islamicization of radicalness.

Roy’s analysis is sharp, but it is also narrow. It ignores a critical historical dimension to this phenomenon, one that is particular, if not unique to France. This is not the first time the country finds that a small, but determined percentage of its youth has been captured by the glorification of violence, the polarization of the world between “them” and “us,” and a fascination with death. Long before the youthful rapture of radical action found expression in militant Islamism, it inhabited other forms of political and ideological extremism in France. So much so as to suggest a singular continuity between the murderous youths who now identify with the IS and the grim history of France’s extreme rightwing movements.

The university students who, in interwar France, joined the extreme rightwing Action Française carried canes, not Kalishnikovs. But these young men, who called themselves the camelots du roi, used the canes not to walk, but to maim their political opponents. Like their analogues with the Islamic State, the camelots were rebelling, in principle, against the perceived decadence and decay of liberal and secular society (symbolized then as now by Jews). In reality, though, they were even more enamored of street brawls and bashing of heads—the embodiment, they believed, of an élan vital unknown to their bourgeois parents. For more than a decade, their presence lent a deliberate element of terror to the boulevards and streets of Paris.

One generation later, during World War II and the German occupation of France, a swathe of French youth betrayed the same fascination with violence. When the Vichy regime created la milice, a paramilitary militia whose purpose was to hunt down resistance fighters and Jews, as well as terrorize the French civilian population, thousands of young men joined its ranks. (According to the historian Robert Paxton, the milice numbered upwards of 45,000—a number that dwarfs French recruits to IS.) A number of factors drove recruitment, including the hope for steady employment and the means to avoid being sent to work in German factories. But there was also, for many, the sheer desire to break violently with their backgrounds and reinvent themselves through violent action.

The most celebrated, and controversial, case for this type of recruit in Louis Malle’s film “Lacombe, Lucien.” Written by the Nobel Prize laureate Patrick Modiano, the film portrays a young provincial man who is equally indifferent to all of the era’s “isms”. Motivated solely by the desire for action, by being part of a cause, Lacombe first tries to join the Resistance; turned down, he then turns to the milice. In the end, any cause would do for a young man, including a violently anti-Semitic one. It hardly matters that Lacombe does not, at first, even recognize the word “Jew.”

This same desire for action, for breaking with one’s past, galvanized a number of young Frenchmen who joined the Charlemagne Division, which was sent to the Eastern Front to fight the Russians. Not all of the 14,000 who enlisted were animated by anti-communism. Instead, as one member, Christian de la Mazière, recalls in the documentary “The Sorrow and the Pity,” there were those driven by sheer excitement. Like the French-born terrorists packing their bags for Iraq and Syria, French youths like de la Mazière had to go abroad to find adventure. While it was the frozen earth of Russia instead of the desert expanses of Iraq, it meant a welcome rupture with their backgrounds, with a France that either ignored or bored them.

There are, obviously, important differences—cultural and sociological—that distinguish these earlier generations of rightwing radicals from the French-born terrorists of IS. But they all share the taste for extremism—a commonality that means France cannot resolve its predicament uniquely by taking the war to the Islamic State. Sooner or later, IS will inevitably stagger into irrelevance. Once it does, though, there will remain the question of whether a small, but potentially deadly percentage of youths can ever be integrated into French society or brought into the fold of a moderate and republican form of Islam. The history of modern France suggests that, while the banners and causes change, the attraction for revolutionary violence will always remain.

Robert Zaretsky is Professor of French History in the Honors College of the University of Houston and author of Boswell’s Enlightenment.