Poland has withdrawn its highest state honour from Ukrainian President Volodymyr Zelensky, after Kyiv named an army unit after a nationalist group that massacred Polish civilians during World War II. The decision by President Karol Nawrocki threatens to unleash a serious diplomatic crisis between the two neighbours – just days before a major conference on Ukraine’s reconstruction is due to be held in the Polish city of Gdańsk. Story by Charlotte Lam and Antoine Fenaux.​