WARSAW (Reuters) – Poland's president has decided to strip Volodymyr Zelensky of the country's top honor after the Ukrainian president caused outrage by renaming an army unit after the Ukrainian Insurgent Army (UPA), nationalists who massacred Poles in World War Two. President Karol Nawrocki's decision was likely to unleash a severe diplomatic crisis between the neighbors just days ahead of a conference on Ukraine's reconstruction in the Polish city of Gdansk.