Even before the shocking treatment of Volodymyr Zelenskyy in the Oval Office, the US had voted with Russia in the UN. Alarm bells about the security threat now facing Europe were already ringing during JD Vance’s speech in Munich in February, when he questioned the point of defending Europe’s liberal democracies from Russia.

For the countries surrounding Russia, this is not just about impertinence or failing diplomacy but about potentially being wiped off the map.

But they are realising, too, that instead of one “west”, the ideal we so long mythologised even before the collapse of communism, we are – in one of the most important geopolitical shifts in decades – seeing the birth of two.

Many people around the world were delighted with Vance’s Hillbilly Elegy. His bestselling memoir showed that the desire to rebuild a normal life after a pathological childhood can be a breeding ground for populism.

But Vance acts as if a background of hardship and struggle in the American rust belt justifies his disastrous political trajectory. Ultimately, he is completely unconvincing. And not only because, regardless of where he was born, he eventually ended up at Yale law school and is now the US vice-president.

The political consequences of trauma should not be underestimated. However, as both individuals and societies, we have choices in how we deal with negative experiences: we can decide to promote polarisation and resentment, or cultivate solidarity and compassion.

The entire former eastern bloc was once one big “Hillbilly Elegy”. It took immense effort to lift nations ravaged by communist bankruptcy from political, economic and often moral collapse and turn them into members of the European Union and Nato. To be sure, the successful modernisation after 1989 was not free of political mistakes and suffering.

But the division of the continent in 1945 was imposed by the great powers the UK, US and USSR. Our countries were not consulted. The legacy in decades of political and economic stagnation – imposed internationally from above – for us meant poverty, crumbling infrastructure, weak state institutions, and millions struggling with deep uncertainty about their own self-worth. They were often addicted to alcohol, also as a result of Soviet-era social engineering. Being hobbled with this unasked-for legacy did not stop us often being branded laggards or deemed less civilised than our western neighbours as we struggled to catch up.

The goal remained clear to us, however: we had to first re-establish our democratic nation states and then set off on a great race to match western standards. Our westernisation was one of enthusiasm, but also of naivety. In a sense, we were like Aeneas, the hero of Greco-Roman mythology, forced to leave behind the world we had known to build something new.

More than three decades after 1989, the transformation of central and eastern Europe is astonishing. Although the fear of losing our sovereignty again has never really gone away, in Tallinn, Vilnius or Bratislava, confident, gleaming modernity now mingles with the remnants of a communist past. Clean streets, sleek new trams, and a feverish drive to renovate everything reflect not just economic growth but a deeper ambition to belong – to prove we were worthy of this, mostly imagined, west.

This path coincided with our coming of age as democracies. But the experience of seeing populist rule take hold in many countries – Brexiters winning in the UK, the full-scale Russian attack on Ukraine – has brought about a new clarity.

It is as if history has reverted. We westernised to achieve democratic maturity. Now it is western Europe that has to “easternise” to achieve maturity in security and defence.

But the global west that we aspired to join is bifurcating; splitting into liberal democratic and populist camps, between resentment and solidarity. Those in power in Washington appear to support the dismantling of the very democratic guiding principles and ideals that helped us to overcome our past misery. The same principles and ideals have allowed Ukraine to resist brutal Russian aggression and retain hope of joining the western institutions.

One of the two new wests belongs to Vance, Donald Trump and their European followers in Hungary, Slovakia and elsewhere.

The other west still cares about constitutionalism and universal human rights. And this democratic west has, for the first time, begun to share the concerns of post-communist Europe about sovereignty. People in our region have lived with existential fear for a long time. It is why Poland and the Baltic countries spend record amounts of their GDP on their military, at the expense of other needs.

Now, at last, Emmanuel Macron, Keir Starmer and the incoming German chancellor Friedrich Merz are willing to see things from Ukraine’s perspective. The summit in London on Sunday confirmed it. Remember, the anxiety was not equally shared before February 2022, when Ukraine’s warnings were often dismissed as “Russophobia” or “hawkish”.

Since then, much has been written about the EU’s centre of gravity shifting from France and Germany towards the Baltic countries and Poland. If this is true it is because Russia’s direct neighbours were willing to take on a disproportionate share of the burden of opposing Russia and then start working on the genuine defence of Europe.

But Germany’s election, in which the Russia-friendly far-right Alternative für Deutschland (backed by Vance) took second place, reminds us that in the new bifurcated west, Europe is also divided: only one part is loyal to liberal democratic values. It understands that solidarity is not a question of appealing to the world’s conscience or shrieking about historic responsibility, sacrifice and enormous cost. Rather it is a question of self-interest.

Vance’s demeaning treatment of Zelenskyy in the Oval Office symbolised something else. Vance was once a fierce critic of Donald Trump, then he suddenly switched sides. In the Oval Office, Hillbilly Elegy morphed into a Hillbilly eulogy for the bullying of those in need of solidarity and compassion. His brand of neo-conservatism looks like ordinary old-school conformism to the doctrine of might is right, strong countries despising or attacking smaller ones.

With the west splitting in two, saving a free Ukraine and defending liberal democracy looks daunting. But it is clearer than ever that the two go hand in hand.

• Karolina Wigura is a Polish historian and co-author of Post-Traumatic Sovereignty: An Essay (Why the Eastern European Mentality is Different)

• Jarosław Kuisz is editor-in-chief of the Polish weekly Kultura Liberalna and the author of The New Politics of Poland: A Case of Post-Traumatic Sovereignty