Poland’s president Karol Nawrocki has threatened to strip Volodymyr Zelenskyy of Poland’s highest state honour after the Ukrainian leader awarded a military unit the honorary title “Heroes of the UPA”.

For many Ukrainians, the massacre is one episode in a longer and more complex history

On 26 May, Zelenskyy signed a decree awarding a Ukrainian special forces unit the honorary title “Heroes of the UPA”, referring to the Ukrainian Insurgent Army, a controversial WWII-era nationalist group.

The Ukrainian leader’s decision proved contentious in Poland, where the UPA is primarily remembered for mass killings carried out in the Volhynia region and Eastern Galicia, in which as many as 100,000 Polish civilians, among them women, children, and the elderly, were murdered. In Poland, this event, commonly referred to as the Volhynia massacre, is broadly regarded as an act of genocide.

The move provoked an immediate backlash in Poland. Lech Wałęsa, the Solidarity leader, Nobel Peace Prize laureate and former president, announced that he would no longer wear a Ukrainian flag on his lapel, while Nawrocki declared his intention to strip Zelenskyy of the Order of the White Eagle, Poland’s highest state honour.