‘I was only ever afraid of signs and symbols, never of people and things, ‘ wrote Romanian writer Mikhail Sebastian in a wonderful book of 1934 that captures the stifling atmosphere of anti – Semitism and toxic nationalism in his country between the two world wars. Today in Europe and the US there’s a lot of talk about the 1930s returning, as fears of rising nationalism take hold. But here’s the paradox: several studies show that nationalistic attitudes, particularly anti-migration sentiment, haven’t changed much in the past 20 years. People have always been uncomfortable with the idea of foreigners settling in their country.

So the question isn’t so much about where nationalism has come from but where it’s been hiding all these years. What is there about ethno-nationalism now that rallies voters, but hasn’t done so before? Is it enough to point to the impact of the 2008-2010 financial crisis, combined with the shock caused by the refugee crisis? Might there be another, less obvious explanation?

Earlier this year, in an exhibition in Sofia by the Bulgarian artist Luchezar Boyadjiev, I came across the perfect visualisation of what has long been the politically correct version of European history. Titled On Holiday, it showed the famous statue, on Berlin’s Unter den Linden boulevard, of the Prussian leader Frederick the Great on horseback – only without the king on the horse’s back. By removing the rider, the artist had transformed the monument of a national hero into a monument of a horse. All the complexities attached to an important but morally controversial figure of the past were suddenly eliminated. There was a double irony to Boyadjiev’s work, directed both to those who expect to see their national leaders on the horseback, and those who hope to rewrite history by simply removing a king.

What Boyadjiev was perhaps unaware of is that when historical heroes are taken off their horses, current political leaders will be tempted to jump on. This is exactly what’s happened in central Europe in recent years. Rightwing political hegemony in such countries as Poland and Hungary is the direct outcome of a void left by the divorce between liberalism and nationalism in the late 1990s.

Remember how nationalists and liberals were allies in the overthrow of communism in 1989. Central European liberals were aware of the political appeal of post-communist nationalism, so they did a lot to shape it and soften it. Appealing to national sentiment was critically important as a way of mobilising society against the communist regimes. Poland’s Solidarity movement was not liberal, but a mixed – social and nationalist – coalition that endorsed the values of liberal democracy.

This alliance between nationalists and liberals came to an end during the Yugoslav wars. The violent breakup of the country persuaded liberals that nationalism was the very heart of darkness, and that flirting with it could only be sinful. Those dramatic events silenced nationalists, or made them less audible – at least for a while. The Serbian leader Slobodan Milošević, a former communist, became the odious symbol of post-1989 nationalism. Unwilling to share a label with him, central and eastern Europe’s nationalist-minded politicians, most of whom were strongly anti-communist, became more muted. Their brand of nationalism simply could not speak its name.

The Yugoslav wars made it impossible for liberals to define liberalism as anything but anti-nationalism. Over time, however, the equating of liberalism with anti-nationalism came at a cost. It eroded electoral support for liberal parties, making them totally dependent on the success of economic reforms and depriving them of powerful nationalist symbols. Meanwhile, an undeclared war between liberals and nationalists led to moderate nationalists being pushed to the illiberal camp.

The example of Germany played a role. Central and eastern European liberals wanted societies to cope with their past much in the same way Germany had coped with its own. But was it realistic to expect that after 1989, we would all become Germans?

Postwar German democracy was built on the assumption that nationalism leads ineluctably to nazism. As a result, any expression of ethno-nationalism came close to being criminalised – even the national flag at football games was viewed with suspicion. Germany’s radical approach isn’t difficult to understand, given the exceptional nature of the Nazi legacy it had to deal with. But the attempt to transfer this to central Europe was bound to backfire.

That’s because central and eastern states were children of the age of nationalism that followed the breakup of Europe’s empires. But unlike German nationalists in 1945, central European nationalists in 1989 felt they’d come out the winners, not the losers, of the last war – in this case the cold war. In that sense, to “become German” was impossible: most Poles felt it absurd to stop honouring nationalist-minded leaders who had risked their lives to defend Poland against Hitler or Stalin.

Today we see the result. In the 19th century, and again in the 1970s and 80s, liberals and nationalists were able to shape a common platform – one that was inclusive, rooted in a culture of individual rights, and centred around a sense of national pride. But today’s central European nationalism has been narrowed down to ethnicism, fuelled by demographic fears and anxieties over Europe’s changing role in the world. Central European nations feel threatened not so much by migrants (who are in fact reluctant to settle in their countries) but by the void left in communities by the economic emigration over the last decade of so many of their citizens, creating a feeling of collective loss in those left behind.

Liberals may dream of defeating nationalism just as nationalism itself helped defeat communism. But that hope is fast turning into political tragedy – because while communism was a radical political experiment based on abolishing private property, nationalism – in one form or another – is an organic part of any democratic political scene. Acknowledging this must surely be part of addressing its growing influence.