At dawn on 10 May, the Germans began an invasion of Belgium and the Netherlands. Accordingly, convinced that they were facing a repeat of the German strategy of 1914, Allied commanders moved the bulk of their forces from the Franco-Belgian border into defensive positions within Belgium to await the continuation of the German attack. In so doing, they fell right into Hitler's trap.
Ellis, as well as Zaloga in his study of the Polish Campaign in 1939, points to the effective use of other arms such as artillery and aerial firepower as equally important to the success of German (and later, Allied) operations. Panzer operations in Russia failed to provide decisive results; Leningrad never fell despite an entire Panzer Group being assigned to take it, nor did Moscow. In 1942 panzer formations overstretched at Stalingrad and in the Caucasus, and what successes did take place - such as Manstein at Kharkov or Krivoi Rog - were of local significance only.
The death camp and slave-labour camp were interrelated. Newly arrived prisoners at the death camp were divided in a process known as Selektion. The young and the able-bodied were sent to work. Young children and their mothers and the old and infirm were sent directly to the gas chambers. Thousands of prisoners were also selected by the camp doctor, Josef Mengele, for medical experiments. Auschwitz doctors tested methods of sterilization on the prisoners, using massive doses of radiation, uterine injections, and other barbaric procedures. Experiments involving the killing of twins, upon whom autopsies were performed, were meant to provide information that would supposedly lead to the rapid expansion of the “Aryan race.”
Remarkably, there were instances of individual resistance and collective efforts at fighting back inside Auschwitz. Poles, Communists and other national groups established networks in the main camp. A few Jews escaped from Birkenau, and there were recorded assaults on Nazi guards even at the entrance to the gas chambers. The 'Sonderkommando' revolt in October 1944 was the extraordinary example of physical resistance.
British theorists J.F.C. Fuller and Captain B. H. Liddell Hart have often been associated with blitzkrieg's development, though this is a matter of controversy. The British War Office did permit an Experimental Mechanised Force, formed on 1 May 1927, that was wholly motorized including self propelled artillery and motorised engineers. It is argued that Guderian, a critical figure in blitzkrieg's conception, drew some of his inspiration from Liddell Hart. This was based on a paragraph in the English edition of Guderian's autobiography in which he credits Liddell Hart. In opposition, it is argued that Liddell Hart, as editor of the autobiography's English edition, wrote that paragraph himself or, more broadly, that his influence on Guderian was not as significant as held. Fuller's influence is less clear. During the war, he developed plans for massive, independent tank operations and was subsequently studied by the German leadership. It is variously argued that Fuller's wartime plans and post-war writings were an inspiration, or that his readership was low and German experiences during the war received more attention.
On 31 July 1941, Hermann Göring gave written authorization to Reinhard Heydrich, Chief of the Reich Security Head Office (RSHA), to prepare and submit a plan for Die Endlösung der Judenfrage (the Final Solution of the Jewish question) in territories under German control and to coordinate the participation of all involved government organizations. Plans for the extermination of the European Jews—eleven million people—were formalized at the Wannsee Conference in Berlin on 20 January 1942. Some would be worked to death and the rest killed. Initially the victims were killed with gas vans or by Einsatzgruppen firing squads, but these methods were impractical for an operation of this scale. By 1942, killing centers at Auschwitz, Sobibór, Treblinka, and other extermination camps had become the primary method of mass killing.
Despite the continuing war with Great Britain, German forces invaded the Soviet Union in June 1941. At first, the German Blitzkrieg seemed to succeed. Soviet forces were driven back more than 600 miles to the gates of Moscow, with staggering losses. In December 1941, Hitler unilaterally declared war on the United States, which consequently added its tremendous economic and military power to the coalition arrayed against him. A second German offensive against the Soviet Union in 1942 brought German forces in the east to the shores of the Volga River and the city of Stalingrad. However, the Soviet Union launched a counteroffensive in November 1942, trapping and destroying an entire German army at Stalingrad.
Allied air superiority became a significant hindrance to German operations during the later years of the war. Early German successes enjoyed air superiority with unencumbered movement of ground forces, close air support, and aerial reconnaissance. However, the Western Allies' air-to-ground aircraft were so greatly feared out of proportion to their actual tactical success, that following the lead up to Operation Overlord German vehicle crews showed reluctance to move en masse during daylight. Indeed, the final German blitzkrieg operation in the west, Operation Wacht am Rhein, was planned to take place during poor weather which grounded Allied aircraft. Under these conditions, it was difficult for German commanders to employ the "armoured idea" to its envisioned potential.
As Soviet troops approached Auschwitz in January 1945, most of its population was sent west on a death march. The remaining prisoners were liberated on 27 January 1945, a day commemorated as International Holocaust Remembrance Day. In the following decades, survivors such as Primo Levi, Viktor Frankl, and Elie Wiesel wrote memoirs of their experiences in Auschwitz, and the camp became a dominant symbol of the Holocaust. In 1947 Poland founded the Auschwitz-Birkenau Memorial and Museum on the site of Auschwitz I and II, and in 1979 it was named a World Heritage Site by UNESCO.
Oskar Schindler (28 April 1908 – 9 October 1974) was a German industrialist and a member of the Nazi Party who is credited with saving the lives of 1,200 Jews during the Holocaust by employing them in his enamelware and ammunitions factories in occupied Poland and the Protectorate of Bohemia and Moravia. He is the subject of the 1982 novel Schindler's Ark and its 1993 film adaptation, Schindler's List, which reflected his life as an opportunist initially motivated by profit, who came to show extraordinary initiative, tenacity, courage, and dedication to save the lives of his Jewish employees.