EUROPE has slipped into a form of “civil war,” fears Emmanuel Macron, France's president. The trenches have been dug, the weapons loaded, the front lines drawn. On one side stand the defenders of Europe’s liberal order, fighting for progress, openness and the values embodied in the mission of the European Union.

Opposing them stand supporters of an earthier politics, grounded in tradition, wedded to nation and suspicious of change, especially if it is delivered by outsiders. These warriors band under the standard of “illiberal democracy,” a term created in the 1990s by Fareed Zakaria, an Indian-American pundit, but given political life by Viktor Orban, Hungary's anti-immigration prime minister.

The antagonists do not fall neatly into geographical camps. Here in the liberal platoon is Donald Tusk (pictured above left at the European Council leaders’ summit), a former prime minister of Poland, shoulder-to-shoulder with Angela Merkel, Germany's chancellor. Glaring at them across no man's land, alongside Mr Orban, stand Geert Wilders, the Dutch anti-Islam fanatic, and Marine Le Pen, the French nationalist. Several eastern European countries, such as the three Baltic states, have built robust democracies, largely free from graft. And the societies of Hungary and especially Poland are streaked with political division. Indeed, Mr Orban and Jaroslaw Kaczynski, Poland's de-facto leader, thrive on such polarisation, denouncing their domestic opponents as traitors, cretins or effete vegetarian cyclists.

For westerners, the EU meant winnowing sovereignty; for easterners it was a way to ensure sovereignty

But it is true that full-spectrum liberalism—embracing strong institutions and cosmopolitanism as well as openness to trade and markets—has rarely been a potent political force in eastern Europe. In part this is because the countries there have known freedom for only a few decades, often with little or no tradition of the institutions essential to well-functioning democracies: strong bureaucracies, independent judiciaries and free media.

At the margin, that weakens the potential resistance when Messrs Orban and Kaczynski set about undermining these alternative centres of authority, or oligarchs concentrate power and wealth in their hands. And few ex-communist countries have a history of immigration from other continents, beyond a few tens of thousands of Vietnamese that found their way to Poland and Czechoslovakia during the Cold War.

Western Europeans often overlook the distinct national character of the post-1989 revolutions and how that defined the region’s accession to the EU. For many westerners the point of the EU is to bind countries into a peace project that also delivers economic benefits by obliging them to pool sovereignty; “nationalism” thus becomes a dirty word.

But for easterners, joining the EU was in part a guarantee of the national sovereignty that had been squashed during decades of subjugation by the Soviet empire. In their haste to embrace a “back to Europe” narrative that smuggles in the liberalism that marked democracy’s march in their half of the continent, well-meaning westerners have overlooked the rather different journey taken by the east. That has become a problem.

Still, the “illiberal democracy” framing has its limits. Jan-Werner Müller, a politics professor at Princeton, argues that the term both flatters the undemocratic tendencies of leaders like Mr Orban, and cedes to them the terms of a culture war that they are only too happy to wage. Mr Orban’s regime is demolishing Hungary’s institutions while lining the pockets of his pals. His latest wheeze is to present himself as the champion of European Christian democracy, but a better label for his rotten regime would be authoritarian kleptocracy.

Similar dynamics may be observed, to lesser and varying degrees, in countries such as Romania and Slovakia, and potentially the Czech Republic. Some of the aspirant countries of the western Balkans are treading this path, too. (Poland has not yielded to large-scale graft, but its leadership’s obsession with overturning the post-1989 settlement appears to override any commitment to democratic norms).

A separate but related aspect is the growth of illegal immigration as a European problem. For the countries that only recently restored their own sovereignty, signing on to the EU did not imply a commitment to multiculturalism, just as joining the passport-free Schengen area had nothing to do with establishing functional asylum systems. Many easterners look at western European cities and see only terrorism and segregation.

No doubt some eastern European leaders cynically exploited voters’ fears about refugee flows that barely grazed their countries. But the ill-considered push, by Germany and others, for compulsory relocation of asylum-seekers across the EU both alienated moderates in the east and presented Mr Orban with the perfect electioneering tool. If "illiberalism" means the freedom to choose who may or may not live in your country, then Mr Orban will happily don the mantle—and most of his compatriots will agree.

For countries that only recently restored their own sovereignty, signing on to the EU did not imply a commitment to multiculturalism.

However it is waged, this battle could be decisive for Europe’s long-term future. Mr Orban is more opportunist than strategist (and has a well-concealed pragmatic streak). But if the EU can find no way to maintain its unity as a club of democracies governed by the rule of law, a different future may loom, with smaller numbers of countries integrating further, and signing up to deeper commitments, while looser trading ties bind a larger club. Mr Macron could probably live with that. Germany, which has always shrunk from such proposals, could not.

To avoid that prospect, defenders of Europe’s rules must pick their battles. Democratic backsliding is a serious problem in a club membership of which is supposed to provide the kitemark for good governance. Resisting that, rather than fretting about illiberalism, must be where the opponents of Mr Orban and his ilk devote their efforts. Identify a culture war, and you may find yourself waging one.