Killing on a mass scale using gas chambers or gas vans was the main difference between the extermination and concentration camps. From the end of 1941, the Germans built six extermination camps in occupied Poland: Auschwitz II-Birkenau, Majdanek, Chełmno, and the three Operation Reinhard camps at Belzec, Sobibor, and Treblinka II. Maly Trostenets, a concentration camp in the Reichskommissariat Ostland, became a killing centre in 1942. Gerlach writes that over three million Jews were murdered in 1942, the year that "marked the peak" of the mass murder of Jews. At least 1.4 million of these were in the General Government area of Poland.
German-occupied Denmark rescued most of its own Jews by spiriting them to Sweden by sea in October 1943. This was possible partly because the German presence in Denmark was relatively small. Moreover, while anti-Semitism in the general population of many other countries led to collaboration with the Germans, Jews were an integrated part of Danish culture. Under these unique circumstances, Danish humanitarianism flourished.
Hitler’s Wehrmacht suffered its first major defeat outside Moscow in December 1941. This put an end to the blitzkrieg as a phenomenon of that period of history. However, three and a half more years of bloody battles lay ahead as part of World War II, which saw the Soviet Union, the United States, the United Kingdom, China and France act as allies against a most dangerous common enemy.
Blitzkrieg sought decisive actions at all times. To this end, the theory of a schwerpunkt (focal point) developed; it was the point of maximum effort. Panzer and Luftwaffe forces were used only at this point of maximum effort whenever possible. By local success at the schwerpunkt, a small force achieved a breakthrough and gained advantages by fighting in the enemy's rear. It is summarized by Guderian as "Nicht kleckern, klotzen!" ("Don't tickle, smash!")
Schindler started out as a wartime profiteer, having acquired an enamelware factory in Poland in 1939. At the height of his business, Schindler had 1,750 workers under his employment — 1000 of them Jewish. Over time, his daily interactions with his Jewish workers prompted him to use his political connections as a former German spy and his wealth to bribe Nazi officers to prevent his workers from being deported and killed. Through various Jewish administrators came what was known as "Schindler's List," although in reality, there were nine separate lists and Schindler, at the time, did not oversee the details since he was incarcerated for suspicion of bribery.
Repeat selections took place several times during the day in roll calls. Inmates who had become weak or ill were separated from the ranks and sent to the gas chambers. A brutal regimen based on a set of punishments and torture was invoked in the camp. Few managed to survive. In Auschwitz-Birkenau, more than 1,100,000 Jews, 70,000 Poles, 25,000 Sinti and Roma (Gypsies) and some 15,000 prisoners of war from the USSR and other countries were murdered.
In the Sinai and Palestine Campaign, operations involved some aspects of what would later be called blitzkrieg. Key elements in the "blitzkrieg warfare" at the decisive Battle of Megiddo included concentration, surprise and speed; success depended on attacking only in terrain favoring the movement of large formations around the battlefield and tactical improvements in the British artillery and infantry attack. General Edmund Allenby used infantry to attack the strong Ottoman front line in co-operation with supporting artillery, augmented by the guns of two destroyers. Through constant pressure by infantry and cavalry, two Ottoman armies in the Judean Hills were kept off-balance and virtually encircled during the Battles of Sharon and Nablus (Battle of Megiddo).
Schindler grew up in Svitavy, Moravia, and worked in several trades until he joined the Abwehr, the military intelligence service of Nazi Germany, in 1936. He joined the Nazi Party in 1939. Prior to the German occupation of Czechoslovakia in 1938, he collected information on railways and troop movements for the German government. He was arrested for espionage by the Czechoslovak government but was released under the terms of the Munich Agreement in 1938. Schindler continued to collect information for the Nazis, working in Poland in 1939 before the invasion of Poland at the start of World War II. In 1939, Schindler acquired an enamelware factory in Kraków, Poland, which employed at the factory's peak in 1944 about 1,750 workers, of whom 1,000 were Jews. His Abwehr connections helped Schindler protect his Jewish workers from deportation and death in the Nazi concentration camps. As time went on, Schindler had to give Nazi officials ever larger bribes and gifts of luxury items obtainable only on the black market to keep his workers safe.