Poland's president has called for the withdrawal of the country's highest state decoration from Ukrainian President Volodymyr Zelenskyy, after Kyiv renamed a military unit in honour of fighters responsible for the deaths of tens of thousands of Polish civilians during the Second World War. The move has provoked a sharp diplomatic rupture between two countries that have been close allies since Russia's full-scale invasion of Ukraine in February 2022.

Earlier this week, Zelenskyy signed a decree designating a Ukrainian special operations unit as the "Heroes of the UPA" — a reference to the Ukrainian Insurgent Army (Ukrainska Povstanska Armiya), the military wing of the Organisation of Ukrainian Nationalists (OUN). The UPA fought for Ukrainian independence during and after the war, resisting both Nazi Germany and the Soviet Union, and is regarded as a heroic symbol by many Ukrainian nationalists. However, between 1943 and 1945, UPA forces carried out a large-scale ethnic cleansing campaign in Volhynia — a region that was then part of Poland and now forms part of western Ukraine — in which an estimated 100,000 Poles were killed. Retaliatory violence also claimed the lives of thousands of Ukrainians.

Polish President Karol Nawrocki said he was "outraged" by the decree and called on the Chapter of the Order of the White Eagle — the advisory body that oversees Poland's top state honour — to convene on 8 June to discuss revoking the award, which was bestowed on Zelenskyy in 2023. Prime Minister Donald Tusk, while expressing hope that both leaders would rise above the historical grievance and preserve essential bilateral cooperation, said the naming "wounds our historical sensitivity" and was "worrying from the point of view of our relations." Nobel Peace Prize laureate and former Polish president Lech Wałęsa, who played a central role in ending communist rule in Poland in 1989, announced he would stop wearing a Ukrainian flag pin in protest, writing on Facebook that Zelenskyy had "insulted me and all our massacred compatriots."

The controversy comes as Zelenskyy has been invoking Ukrainian nationalist historical figures in an apparent effort to strengthen national unity against Russia. Also this week, Kyiv repatriated and reburied the remains of Andriy Melnyk, a founding leader of the OUN, from Luxembourg. Ukraine has also launched a project to build a national monument honouring figures from its independence movement.

The dispute matters because Poland has been one of Ukraine's most strategically important supporters — serving as a key transit hub for Western military aid and a vocal advocate for Kyiv within the European Union and NATO. A serious deterioration in relations between the two neighbours would carry consequences not only diplomatically but potentially for the flow of support that Ukraine depends on to sustain its war effort. Tusk's call for both sides to manage their differences reflects the difficult balance Warsaw must strike between historical memory and geopolitical necessity.