Rabbi Jacob J. Schacter was visiting the cemetery for U.S. soldiers in Normandy when something struck the professor of Jewish history at Yeshiva University as odd: There seemed to be too few non-Christian graves. That insight in 2014 resulted in a nonprofit project that tracks down the graves of Jewish U.S. servicemen mistakenly buried under crosses, to give them Star of David headstones. Operation Benjamin has so far replaced the headstones of 19 U.S. Jewish servicemen, including seven who underwent the ceremony last week in cemeteries in France, Belgium and Luxemburg, the Military Times reported. The group’s first successful identification...