We are taught to think of minorities as a problem European states have not yet managed to solve.
It is the wrong way round. Minorities are a problem European states were built to eliminate.
In 1648, after thirty years of religious war that killed an estimated eight million people, Europe's powers met in Osnabrück and Münster and made peace. Westphalia is celebrated as the birth of the modern state system: sovereignty, the equality of states, the beginnings of international law. Those are real achievements.
But the peace rested on a formula. Cuius regio, eius religio. Whose realm, his religion. If the prince was Catholic, the state was Catholic. Those who could not conform could, at best, leave.
Homogeneity was the price of peace. And the idea did not stay with religion. If a stable state needed one faith, it needed one culture. If one culture, one language. If one language, one people, bound by something deeper than law.
France is the clearest case. The Republic did not simply govern its diversity. It dismantled it. Breton, Occitan, Basque, Corsican, Flemish: each was suppressed through the schools, and children were punished for speaking their mother tongue.
Laïcité was forged in that project. It was not built for Islam. It was built for the Catholic Church, as the state's weapon for asserting its supremacy over religious authority. Once forged, it was available for anyone.
Germany ran the same programme in the 1870s. Bismarck's Kulturkampf put Catholic orders under state supervision, expelled the Jesuits as agents of a foreign power, and demanded that Catholics prove their loyalty by conforming. Today German Muslim organisations are watched by the domestic intelligence service, and politicians debate expelling foreign-trained imams as agents of Ankara. The century changed. The logic did not.
The school is the quiet instrument. My children leave the house carrying more than one language and more than one sense of who they are. They spend the day inside an institution built to produce a national subject. Nobody there intends to erase anything. It does not need intent. The erasure is architectural.
Here is why Muslims sit so badly in this machine. Breton identity could be absorbed because it was local. It never claimed to be universal. Islam does. The Westphalian state can live with a private faith that accepts the state as the final authority. It cannot live with a rival universalism, a faith that says God's law is not subordinate to any human one, and the community of believers not subordinate to any flag.
That is the real incompatibility. Not with democracy, in which Muslims take part across Europe. Not with the rule of law. With the state's demand for a monopoly on meaning.
Westphalia promised peace through sameness. It is now delivering exclusion by the same rule. The question is not whether you can be absorbed. It is whether you are willing to be.