WSJ reporters Chow, Schechner and Kostov provide this exceptional report from the 11th Arondissement in France, scene of the terrorist attacks in Nov. 2015, describing the conflicting visions of French society- one secular and the other in other parts of the country anti-immigrant. The National Front of Marie Le Pen sees immigration as "a mortal threat to France" and won about 25% of the vote in France in the 2014 European parliament elections, a first for a anti-immigrant party in Europe. It did very well in rural areas and small towns of northwest France and southern France. The debate on immigration is now dominating headlines in Europe, including Denmark, Norway, Germany, France, Rumania, Hungary, and other countries. The Syrian refugee crisis has exacerbated the situation.