Populists appear childish not just in their impetuous mannerisms, but because they display no historical depth, no learning from experience. Many commentators and analysts have attempted to find what is common to Trump’s supporters. They usually use the familiar categories of class, ethnicity, gender, age, and personal economic relation to globalization. There is yet another relevant category: ignorance of history.

Today’s populism advocates an amalgam of policies that failed in the past two centuries, leading to two world wars and the deepening of the economic depression of the 1930s: Blocking international trade routes and breaking production chains through barriers and tariffs, turning away refugees, and scapegoating ethnic and religious minorities for economic difficulties. A Europe of truly independent nation-states will restore the mentality of the great-power politics of the 19th century, only without the power: Russia will emerge strongest from the process of renationalizing security policies.

Populism was not supposed to happen. During the 20th century, humanity subjected itself to a painful learning process by trying ideologies from the totalitarian extremes of the conventional Right and Left. The extreme Right led to the catastrophe of World War II. The extreme Left collapsed with the Soviet Bloc in 1989. At the end of the Cold War, Francis Fukuyama argued that humanity had learned its lesson and, by elimination, only liberal democracy was left standing at the (philosophical, not literal) end of history. A minor assumption in Fukuyama’s reasoning was that nations do learn from history, retain the lessons, and pass them down through the generations. He did not examine at any length the possibility that societies might not remember failed historical experiments and so unwittingly repeat versions of them.

Alas, it happens.