Polish President Andrzej Duda signed a controversial law criminalizing statements that attribute responsibility for the Holocaust and other Nazi atrocities to “the Polish nation.”

The law is just the latest part of a broader effort at historical revisionism.

Nor is Poland the only postcommunist country that has tried to reframe the history of its role in World War II and defend the part it played in the Holocaust. Hungary, Ukraine, and the Baltic states have all made similar moves.

ascendant right-wing populist parties across Europe mean that the union no longer speaks with one voice. Sanctioning a member state is now more difficult.Right-wing populist politicians, traditionally Euroskeptics, are now even more willing to invite international disapproval and gain domestic popularity by stoking nationalism and whitewashing the past.

In states that experience direct threats from Russia and are ruled by right-wing populist parties, the trend toward policing history and silencing inconvenient facts about their roles in World War II is likely to continue. That will heighten tensions with the United States and Israel, divide allies even within eastern Europe, and stifle open debate. Ironically, it is Putin’s autocracy that might benefit the most from these developments.