There is a dividing line across the middle of Europe, between the intolerant and the tolerant. East of that line, a majority or strong plurality of voters have elected parties of ethnic nationalism that demonize religious and ethnic minorities, shut borders to newcomers and shun international co-operation.
It's a new line that follows an old path: Starting at the Baltic Sea, cutting through the middle of Germany and then down toward Greece. It is the old Iron Curtain. Intolerant extremism is triumphing in most of the countries that were communist before 1989.
The line became more stark and visible in October, when Czechs elected a government led by Andrej Babis, a brash-talking billionaire in a Trumpite mould who ran against immigration and the European Union. In this, he is strongly aligned with the Law and Justice party of Poland, which has governed since 2015 with a Catholic-chauvinist message opposed to migration and European neighbours (in November, Warsaw witnessed the spectacle of thousands of people marching under banners calling for a "White Europe" and "Death to Enemies of the Homeland"). Likewise, the Fidesz party of Hungary, whose Prime Minister Viktor Orban has demanded border walls, presided over overt and veiled attacks on Jews, Roma and Muslims; and Serbian President Aleksandar Vucic, who, while nominally pro-European, many Serbs believe has led his country in a more ethnic-nationalist and pro-Russian direction. Those German districts that voted heavily for the intolerant Alternative for Germany in November fell exclusively within the borders of the old communist German Democratic Republic.
Why have regions that experienced communism tended to feel the pull of angry identity politics? Some analysts point to the weak institutions and oligarch criminality experienced in the post-1989 transition countries. Others look at the higher poverty levels and greater inequality of those regions. Or to the distrust of even moderately progressive governments resulting from decades under totalitarian rule.
But one explanatory factor really stands out. It also explains why the more multiethnic ex-communist countries, notably the Baltic states and Bosnia, have escaped the ethno-nationalist tide. It is rooted in the decisions that we, the Allies, made at the end of the Second World War.
All of these countries and regions were, at the outset of the 20th century, very ethnically and religiously diverse. Four in 10 Poles weren't ethnically Polish or religiously Catholic; prewar Europe was a very multicultural place.
But in 1945, the Yalta pact negotiated between the U.S., British and Soviet leaders drew new European borders that organized the Central and Eastern European countries strictly along ethnic lines.
As a consequence, the largest ethnic cleansing in history took place after the war, at the behest of the Allies: Tens of millions of ethnic Poles, Ukrainians, Czechs, Hungarians and Germans were expelled, force-marched into the countries that bore the names of their ethnicities, often dying in the process. Then communist governments completed the work of the Nazis, expelling and purging Jews, Muslims and Roma. Four generations have grown up in what are now some of the world's most ethnically homogeneous countries.
I spoke this week with Aviel Roshwald, the Georgetown University historian whose major books and papers have explored the history and persistence of ethnic nationalism in modern Europe. He points to a number of causes, including those mentioned above, but notes that uni-ethnic countries are now seen by many eastern Europeans as a norm.
"Ethnic homogeneity was seen as an achievement, it was the bedrock of political stability under communism and beyond," he says. "For many of these societies, the achievement of ethnic homogeneity was the end product of bloody conflicts. It eliminated mutual territorial claims by making ethnic populations much more congruent with the new borders; the non-territorial minorities such as the Jews were largely gone. So when politicians start talking about immigration and cultural diversity as a threat, people are much more open to that message."
Branko Milanovic, the Serbian-American economist, noted recently that the 1989 anti-communist revolutions were seen by many citizens of the region not as democratic uprisings (which is how Western governments saw them), but as "revolutions of national emancipation." The Eastern-Bloc democratic revolution was "a democracy of convenience, not a democracy of choice" – a delivery mechanism for ethnic and national identity.
The monochromatic politics of ethnic identity aren't unanimous – they attract a narrow half of Poles, three-quarters of Hungarians, fewer than half of Czechs, east Germans and Serbs – and their support is mostly in rural, economically weak regions. But they still have a greater potency east of the old Iron Curtain than elsewhere, for reasons that were rooted in good part in our allies' bad decisions.