Europeans drew the wrong lessons from the American civil-rights movement. In the U.S., there was race and there was immigration. They were separate matters that could (at least until recently) be disentangled by people of good faith. In Europe, the two problems have long been inseparable. Voters who worried about immigration were widely accused of racism, or later of “Islamophobia.”

In France, antiracism set itself squarely against freedom of speech. The passage of the 1990 Gayssot Law, which punished denial of the Holocaust, was a watershed. Activist lobbies sought to expand such protections by limiting discussion of a variety of historical events—the slave trade, colonialism, foreign genocides. This was backed up by institutional muscle. In the 1980s, President François Mitterrand’s Socialist party created a nongovernmental organization called SOS Racisme to rally minority voters and to hound those who worked against their interests.

Older bodies such as the communist-inspired Movement against Racism and for Friendship Among the Peoples made a specialty of threatening (and sometimes carrying out) lawsuits against European intellectuals for the slightest trespasses against political correctness: the late Italian journalist Oriana Fallaci for her post-9/11 lament “The Rage and the Pride,” the philosopher Alain Finkielkraut for doubting that the 2005 riots in France’s suburban ghettos were due to unemployment, the Russia scholar Hélène Carrère d’Encausse for speculating about the role of polygamy in the problems of West African immigrants.