As Poland marks its National Day of Remembrance for the Victims of the Volhynia Massacre on July 11, history and politics have once again moved to the forefront of Polish-Ukrainian relations.

Poland and Ukraine have forged one of Europe’s most consequential strategic partnerships since Russia’s full-scale invasion in 2022, but their latest dispute over historical memory is a reminder that unresolved wounds from the past can still undermine today’s security. At a moment when Kyiv is advancing toward EU accession and relying on Poland to help fend off Russian aggression, such divisions amount to a geopolitical gift for Russian President Vladimir Putin.