U.S. Ambassador Stephen Mull attends ceremonies marking the 72nd anniversary of the Warsaw Ghetto Uprising, in front of the monument to the Heroes of the Ghetto, in Warsaw, Poland, on Sunday, April 19, 2015. A few hundred Jews at the ghetto rose with arms on April 19, 1943 against the Nazi forces who began to transport hundreds of thousands of ghetto residents to the Majdanek death camp. Later Sunday, Mull was summoned to Poland's Foreign Ministry, which protested recent words by FBI director, James Comey, who alleged that the Poles were accomplices of the Germans in the Holocaust. (AP Photo/Czarek Sokolowski)