To say that Europe is united by its divisions is an exaggeration – but only a small one. Closing national borders during the pandemic may have been a rational health response, but the longer term political consequences become more troubling when we look at the order in which European governments began to reimpose frontiers.

Italy made the decision on 10 March, when the number of confirmed cases had already exceeded 10,000. Over the next five days, Slovakia, the Czech Republic, Poland, and Hungary closed their borders one after the other, even though by that time in any of them the number of confirmed Covid-19 cases had not reach a hundred.

As a first impulse, suspending the Schengen border-free zone after years of free movement is understandable. Leaders naturally wanted to act quickly to avoid a dramatic Italian scenario in their territories. Bear in mind, though, that these decisions to limit the free movement of people were made by politicians not by doctors. Just as when Donald Trump imposed his European travel ban selectively at first, the closing of frontiers in central and eastern Europe has a political significance that goes beyond mere sanitary demands. Politics in the time of plague is still politics. (This is why, by the way, the the much-discussed “return of the expert” is a fantasy, at best wishful thinking.)

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The sequence in which the Schengen provisions were suspended in central and eastern Europe tells us something important about societies in this region and perhaps even about the EU in general.

First, there is the collective psychological dimension. The question of borders here is not just about geography or history, it is an existential one. For decades, post-communist countries have sought to escape Soviet influence in order to “return to Europe”. The reasons were only partially economic. In all those memorable pictures of the fall of the Berlin wall in 1989, one can see crowds of east Germans who believed they were literally escaping the trap of history. Poles, Hungarians, Czechs and many other nations felt the same. In the 20th century, their central experience was that of cyclical collapse of their states, downfall of sovereignty and existential threat coming from two totalitarian systems. Their desire to join organisations such as Nato or the EU after the collapse of communism derived from their view that the west was a guarantor of institutional stability and personal safety. Joining the Schengen zone in particular, was seen as a way of finally leaving the geopolitical danger zone.

Those countries should theoretically then have been the last, not the first, to close their borders in 2020. One of the reasons for this is that “returning to Europe” brought on the one hand modernisation and prosperity, but on the other a profound cost. One outcome of Schengen has been the mass emigration of well-educated workers.

The brain drain of doctors has contributed to the dramatic situation facing many healthcare systems in the region. Long before the pandemic, Hungary had considered special contracts for young doctors to stop them emigrating en masse. In Poland, according to official OECD and Eurostat data, the number of practicing physicians per 1,000 inhabitants is only 2.4. Whenthe UK announced new recruitment for the NHS of doctors from the EU, the understanding in Poland was that Britain’s target was not France or Germany but farther east. Closing the borders has in fact been in the central and eastern European air for quite some time and the arrival of Covid-19 is just a catalyst.

In spite of their extraordinary transformation since 1989 the post-communist states are also still perceived (including by their own citizens) as weak. True or false, this provokes neurotic reactions to almost any political threat. Radical political language and radical measures are taken because fear of another collapse of the state is still deep rooted. These real anxieties may gradually be eroding faith in joint EU solutions, such as the Schengen zone, which were previously seen as benign.

The same reasons may explain why, for example, the response of Poles to their lockdown has turned out to be so disciplined and relatively well organised. If the state is weak – including the healthcare system – we want to stay at home and where possible organise for others. Voluntary networks in Poland cooking free meals for doctors or preparing additional Covid-19 tests are examples of such behaviour.

There is therefore something of a perverse relief to the closing of borders in central and eastern European countries because of the pandemic. It might be only a fleeting feeling that will soon give way to a longing for European normality. However, it could also be the other way around.

The second point relates to the way in which exceptional powers are a source of immense temptation for politicians, especially the illiberal populists in our part of Europe. Could they resist the lure of this extraordinary centralisation of power?

In our city, Warsaw, like others around the globe, almost total silence reigns; drones take photographs of empty streets from above. But silence in the public sphere matters. In classical political philosophy it was associated with the danger of despotism. In The Spirit of the Laws Montesquieu writes about the deadly silence in the cities when the enemy is scaling the walls. Our adversary today has no legions. It is invisible – but that does not mean it is less threatening. Contrary to democracy, characterised by a robust and lively public sphere, in despotism people’s interests and activities shift to the private sphere, where they focus on material goods and forget about the community. This threatens democracy, because while people are preoccupied, irreversible changes can be made to the political system.

Silence in the public sphere will not be compensated for by the din online. In a more romantic era we thought the web and social media would give citizens better tools and make them more active. Today the passivity of citizen-followers is a well-established phenomenon, and our worries are about privacy and the lack of regulation of tech platforms. It is hard to assume that the internet will automatically become a remedy for the deserted public sphere.

The spectre of a sanitary cataclysm effectively pushes democracy to the sidelines. In those countries where respect for democracy has been established over many years, it does not have to be dangerous. But things look different in places where illiberal populists have already started to translate the 2020 health emergency as the victory of the nation-state over a helpless EU, and the liberal rules-based multilateral order. In Hungary Viktor Orbán has been allowed to rule by decree during this state of emergency without any clear time limit and special measures include jail terms for spreading misinformation. Since 1989 no politician has been so powerful in the region.

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In Poland, the government changed the electoral law overnight to make sure the 10 May presidential elections go ahead, hoping that the only candidate able to organise a campaign is the current president, Andrzej Duda. Attempts are also being made to stop doctors from criticising the performance of the healthcare system in the face of the pandemic. And in Slovakia, citizens are expressing worries that the special measures introduced by the government will give it uncontrolled access to personal information.

Our collective quarantine could last for weeks or months. In parts of central and eastern Europe there is a threat that it will end in consolidating the illiberal order to an extent difficult to predict. Even from behind their closed borders, illiberal leaders can inspire each other. For, yes, coronavirus can also affect political regimes. And it could permanently change the face of the EU.

• Jarosław Kuisz is a historian, editor-in-chief of the Polish weekly Kultura Liberalna and a fellow at the Institute of Advanced Studies in Berlin

• Karolina Wigura is a historian, political editor of the Polish weekly Kultural Liberalna and a fellow at the Institute of Advanced Studies in Berlin