Polish Prime Minister Donald Tusk said he hopes Ukrainians will rethink their approach to the Volyn tragedy and urged people in Poland to avoid inflaming emotions. [The Volyn (Volhynia) tragedy was a series of events that led to the ethnic cleansing of the Polish and Ukrainian populations in 1943 during World War II. It was part of a long-standing rivalry between Ukrainians and Poles in what is now Ukraine's west. Poland considers the Volyn tragedy a genocide of Poles – ed.]

Poland, steeped in bad memories of the 1939 invasion and decades of Soviet dominance after World War II, is a firm backer of Ukraine’s defense against Russia. But a flare-up over…

Russia has the greatest interest in worsening relations between Poland and Ukraine and would be “overjoyed” if a deep political crisis were to arise between the two countries. —…

Polish Prime Minister Donald Tusk said he hopes Ukrainians will rethink their approach to the Volyn tragedy and urged people in Poland to avoid inflaming emotions. [The Volyn…