EXPLAINER: Why are Poland and Ukraine at odds about their history?

WARSAW — Despite Poland’s strong support for Ukraine in its war against Russia, relations between the two countries have been strained by a dispute over Kyiv’s decision to name a military unit after a nationalist force linked to wartime atrocities against Poles during World War II.

The disagreement has revived long-standing tensions over competing historical narratives, particularly surrounding the Ukrainian Insurgent Army (UPA) and the Volhynia massacres.

Dispute over Ukrainian Insurgent Army reference

Tensions escalated after Polish President Karol Nawrocki revoked Ukraine President Volodymyr Zelenskyy’s top national honor following Kyiv’s decision to recognize a Ukrainian combat unit that adopted the name of the Ukrainian Insurgent Army.

The move, intended by Ukrainian forces to honor historical resistance to Moscow, was widely criticized in Poland due to the UPA’s controversial wartime record.

The Ukrainian Insurgent Army operated during and after World War II, when Ukraine was part of the Soviet Union. The group at times fought against Soviet forces and also cooperated with Nazi Germany in pursuit of Ukrainian independence.

Ukraine has said the naming carries no anti-Polish intent and reflects the legacy of fighters who resisted Russian domination.

However, Polish officials and historians emphasize the UPA’s role in the Volhynia massacres between 1943 and 1945, during which Warsaw estimates that around 100,000 ethnic Poles were killed. Thousands of Ukrainians were also killed in retaliatory violence.

Polish historians describe the killings as genocide aimed at securing ethnic dominance in disputed territories that had belonged to Poland between the two world wars. Kyiv rejects that characterization, arguing the conflict was complex and involved atrocities committed on both sides.

Long-running historical grievances

The dispute has persisted for decades, even as Poland has been one of Ukraine’s most important allies since Russia’s full-scale invasion, providing military assistance and hosting nearly one million Ukrainian refugees.

Post-war population transfers continue to shape historical grievances. In 1947, within Poland’s new postwar borders, approximately 140,000 ethnic Ukrainians and Lemkos were forcibly relocated from southeastern Poland to former German territories. Warsaw describes the operation as a security measure to weaken UPA support networks, while Ukrainian perspectives often view it as ethnic cleansing.

Exhumation requests and renewed tensions

Poland has repeatedly sought access to burial sites in western Ukraine linked to the Volhynia massacres. Progress on these requests has been limited, though recent developments suggest cautious movement.

Poland recently began exhumations in the former village of Puzhnyky, while Kyiv last week approved additional excavation work in the Volhynia region’s Liuboml district.

Rising nationalist rhetoric in Poland

The dispute has also been amplified by domestic politics in Poland. Nawrocki, a conservative historian and nationalist figure inspired by former U.S. President Donald Trump, has accused Kyiv of delaying exhumation permissions and has called for Ukraine to formally recognize the Volhynia killings as genocide.

During his political campaign, Nawrocki also took a harder line on Ukraine’s future NATO ambitions, saying he would not support ratification of Ukrainian accession if it risked escalating tensions with Russia, marking a departure from Poland’s previous policy consensus.

Critics argue that his stance reflects a broader attempt to reshape historical education in Poland in ways that downplay more difficult aspects of the country’s past.

Despite these tensions, both Warsaw and Kyiv continue to maintain strategic cooperation, underscoring the complex balance between historical grievances and present-day security concerns in Eastern Europe. -Reporting by Marek Strzelecki; additional reporting by Anna Wlodarczak-Semczuk; Editing by Kevin Liffey and Milla Nissi-Prussak/Reuters