fleeing the pogroms of Eastern Europe. The flow temporarily halted during World War I but resumed afterwards. The long-established, heavily assimilated Jewish population by 1920 was now only a third of the French Jewish population. It was overwhelmed by new immigrants and the restoration of Alsace-Lorraine. About 200,000 immigrants arrived, 1900 to 1939, mostly Yiddish-speakers from Russia and Poland as well as German-speaking Jews who fled the Nazi regime after 1933. The historic base of traditional Judaism was in Alsace-Lorraine, which was recovered by France in 1918. The new arrivals got along poorly with the established elite Jewish community. They did not want to assimilate, and they vigorously supported such new causes, especially Zionism and communism. The Yiddish influx and the Jewishness of the Popular Front's leader Léon Blum contributed to a revival of antisemitism in the 1930s. Conservative writers such as Paul Morand, Pierre Gaxotte, Marcel Jouhandeau, and the leader of Action française Charles Maurras denounced Jews. Perhaps the most violent antisemitic writer was Louis-Ferdinand Céline, who wrote, "I feel myself very friendly to Hitler, and to all Germans, whom I feel to be my brothers.... Our real enemies are Jews and Masons", and "Yids are like bedbugs". By 1937, even mainstream French conservatives and socialists, not previously associated with antisemitism, denounced the alleged Jewish influence pushing the country into a "Jewish war" against Nazi Germany. The new intensity of antisemitism facilitated the extremism of the Vichy regime after 1940. World War II and the Holocaust When France came under occupation by Nazi Germany in June 1940, about 330,000 Jews lived in France (and another 370,000 in French North Africa). Of the 330,000, fewer than half held French citizenship and the others were foreigners, mostly exiles from Germany and Central Europe who had immigrated to France during the 1930s. Another 110,000 French Jews were living in the colony of French Algeria. About 200,000 Jews, and the large majority of foreign Jews, resided in the Paris area. Among the 150,000 French Jews, about 30,000, generally native to Central Europe, had obtained French citizenship after immigrating to France during the 1930s. Following the 1940 armistice after Germany occupied France, the Nazis incorporated the provinces of Alsace and Lorraine into Germany. The remainder of northern and western France was placed under German military control. Unoccupied southern metropolitan France and the French empire were placed under the control of the Vichy Regime, a