By World War II, nearly all Jewish companies had either collapsed under financial pressure and declining profits, or had been forced to sell out to the Nazi-German government as part of the "Aryanization" policy inaugurated in 1937. As the war started, large massacres of Jews took place. Pogroms (racial riots) were also encouraged by the Nazis, especially early in the war before the larger mass killings began.
The first of these pogroms was Kristallnacht in Nazi Germany, often called Pogromnacht, or "night of broken glass," in which Jewish homes were ransacked in numerous German cities along with 11,000 Jewish shops, towns and villages, as civilians and SA stormtroopers destroyed buildings with sledgehammers, leaving the streets covered in smashed windows — the origin of the name "Night of Broken Glass." Jews were beaten to death; 30,000 Jewish men were taken to concentration camps; and 1,668 synagogues ransacked with 267 set on fire. In the city of Lvov, Ukrainian nationalists organized two large pogroms in July, 1941, in which around 6,000 Jews were murdered.
In Lithuania, anti-Soviet partisan groups engaged in anti-Jewish pogroms on July 25 and 26, 1941, before Nazi forces even arrived, killing about 3,800 Jews and burning synagogues and Jewish shops. Perhaps the deadliest of these Holocaust-era pogroms was the Iaşi pogrom in Romania, in which as many as 14,000 Jews were killed by Romanian citizens, police, and military officials.
By December 1941, Adolf Hitler decided to completely exterminate European Jews. In January 1942, during the Wannsee conference, several Nazi leaders discussed the details of the "Final Solution of the Jewish question" (Endlösung der Judenfrage). Dr. Josef Bühler urged Reinhard Heydrich to proceed with the "Final Solution" in the General Government. They began to systematically deport Jewish populations from the ghettos and all occupied territories to the seven camps designated as Vernichtungslager, or extermination camps: Auschwitz, Belzec, Chelmno, Majdanek, Maly Trostenets, Sobibór and Treblinka II. Sebastian Haffner published the analysis in 1978 that Hitler from December 1941 accepted the failure of his goal to dominate Europe forever on his declaration of war against the United States, but that his withdrawal and apparent calm thereafter was sustained by the achievement of his second goal—the extermination of the Jews.
Even as the German Nazi war machine faltered in the last years of the war, precious military resources such as fuel, transport, munitions, soldiers, and industrial resources were still being heavily diverted away from the war and towards the death camps. By the end of the war, much of the Jewish population of Europe had been killed in the Holocaust. Poland, home of the largest Jewish community in the world before the war, had over 90% of its Jewish population, or about 3,000,000 Jews, murdered by the Nazis. Greece, Yugoslavia, Hungary, Lithuania, Bohemia, the Netherlands, Slovakia, and Latvia each had over 70% of their Jewish population killed.
Belgium, Romania, Luxembourg, Norway, and Estonia lost around half of their Jewish population, the Soviet Union lost over one third of its Jews, and even countries such as France and Italy each saw around a quarter of their Jewish population killed.