Issues of Jewish identity, religion, heritage and oppression are given a fresh spin in Joshua Harmon’s Prayer for the French Republic, a work of considerable length and intellectual heft. Harmon has set his drama in France, America’s oldest ally, which shares its values. Although it is a country closer geographically and emotionally to the harrowing experience inflicted on Jews by World War II and the Holocaust, it stands in for the United States as well. Incidents of anti-Semitism have increased in both countries in the last decade.