Ukraine is now at odds with Poland, one of its closest and most important allies in its effort to defeat Russian aggression, over their fraught historical relationship.The dispute centers on Ukrainian President Volodymyr Zelensky’s decision last month to honor World War II Ukrainian national fighters who fought against the Soviet Union. The Poles consider the Ukrainian Insurgent Army responsible for what they remember as the Volhynia genocide. Since Zelensky signed the decree on May 26, Polish President Karol Nawrocki said he would revoke the country’s highest state award, the Order of the White Eagle, which Zelensky received in April 2023.Zelensky’s...