From 1921 to 1922, Hitler evoked rhetoric of both the achievement of Lebensraum involving the acceptance of a territorially reduced Russia as well as supporting Russian nationals in overthrowing the Bolshevik government and establishing a new Russian government. Hitler's attitudes changed by the end of 1922, in which he then supported an alliance of Germany with Britain to destroy Russia. Hitler later declared how far he intended to expand Germany into Russia:
From as early as 1934, concentration camp commandants used prisoners as forced laborers for SS construction projects such as the construction or expansion of the camps themselves. By 1938, SS leaders envisioned using the supply of forced laborers incarcerated in the camps for a variety of SS-commissioned construction projects. To mobilize and finance such projects, Himmler revamped and expanded the administrative offices of the SS and created a new SS office for business operations. Both agencies were led by SS Major General Oswald Pohl, who would take over the Inspectorate of Concentration Camps in 1942.
The Germans occupied Amsterdam in May 1940. In July 1942, German authorities and their Dutch collaborators began to concentrate Jews from throughout the Netherlands at Westerbork, a transit camp near the Dutch town of Assen, not far from the German border. From Westerbork, German officials deported the Jews to Auschwitz-Birkenau and Sobibor killing centers in German-occupied Poland.
When the 322nd Rifle Division of the Red Army liberated Auschwitz on 27 January 1945, the soldiers found 7,500 prisoners alive and over 600 corpses. Auschwitz II-Birkenau was liberated at around 3:30 p.m., and the main camp (Auschwitz I) two hours later. Items found by the Soviet soldiers included 370,000 men's suits, 837,000 women's garments, and 7.7 tonnes (8.5 short tons) of human hair. Primo Levi described seeing the first four Russian soldiers on horseback approach the camp at Monowitz, where he had been in the sick bay. The soldiers threw "strangely embarrassed glances at the sprawling bodies, at the battered huts and at us few still alive ...":
By early 1934, the focus shifted towards rearmament. By 1935, military expenditures accounted for 73 percent of the government's purchases of goods and services. On 18 October 1936, Hitler named Göring as Plenipotentiary of the Four Year Plan, intended to speed up rearmament. In addition to calling for the rapid construction of steel mills, synthetic rubber plants, and other factories, Göring instituted wage and price controls and restricted the issuance of stock dividends. Large expenditures were made on rearmament in spite of growing deficits. Plans unveiled in late 1938 for massive increases to the navy and air force were impossible to fulfil, as Germany lacked the finances and material resources to build the planned units, as well as the necessary fuel required to keep them running. With the introduction of compulsory military service in 1935, the Reichswehr, which had been limited to 100,000 by the terms of the Versailles Treaty, expanded to 750,000 on active service at the start of World War II, with a million more in the reserve. By January 1939, unemployment was down to 301,800 and it dropped to only 77,500 by September.
In February 1938, Hitler emphasised to Austrian Chancellor Kurt Schuschnigg the need for Germany to secure its frontiers. Schuschnigg scheduled a plebiscite regarding Austrian independence for 13 March, but Hitler sent an ultimatum to Schuschnigg on 11 March demanding that he hand over all power to the Austrian NSDAP or face an invasion. German troops entered Austria the next day, to be greeted with enthusiasm by the populace.
Losses continued to mount after Stalingrad, leading to a sharp reduction in the popularity of the Nazi Party and deteriorating morale.  Soviet forces continued to push westward after the failed German offensive at the Battle of Kursk in the summer of 1943. By the end of 1943 the Germans had lost most of their eastern territorial gains. In Egypt, Field Marshal Erwin Rommel's Afrika Korps were defeated by British forces under Field Marshal Bernard Montgomery in October 1942. The Allies landed in Sicily in July 1943 and in Italy in September. Meanwhile, American and British bomber fleets based in Britain began operations against Germany. Many sorties were intentionally given civilian targets in an effort to destroy German morale. German aircraft production could not keep pace with losses, and without air cover the Allied bombing campaign became even more devastating. By targeting oil refineries and factories, they crippled the German war effort by late 1944.
On 1 September 1939, when Anne was 10 years old, Nazi Germany invaded Poland, and so the Second World War began. Not long after, on 10 May 1940, the Nazis also invaded the Netherlands. Five days later, the Dutch army surrendered. Slowly but surely, the Nazis introduced more and more laws and regulations that made the lives of Jews more difficult. For instance, Jews could no longer visit parks, cinemas, or non-Jewish shops. The rules meant that more and more places became off-limits to Anne. Her father lost his company, since Jews were no longer allowed to run their own businesses. All Jewish children, including Anne, had to go to separate Jewish schools.
By January 1945 Soviet troops were advancing towards Auschwitz. In desperation to withdraw, the Nazis sent most of the 58,000 remaining prisoners on a death march to Germany, and most prisoners were killed en route. When the Soviet army liberated Auschwitz on January 27, soldiers found only 7,650 barely living prisoners throughout the entire camp complex. In all, approximately one million Jews had been murdered there.
The 1930 elections changed the German political landscape by weakening the traditional nationalist parties, the DNVP and the DVP, leaving the Nazis as the chief alternative to the discredited Social Democrats and the Zentrum, whose leader, Heinrich Brüning, headed a weak minority government. The inability of the democratic parties to form a united front, the self-imposed isolation of the Communists and the continued decline of the economy, all played into Hitler's hands. He now came to be seen as de facto leader of the opposition and donations poured into the Nazi Party's coffers. Some major business figures, such as Fritz Thyssen, were Nazi supporters and gave generously and some Wall Street figures were allegedly involved, but many other businessmen were suspicious of the extreme nationalist tendencies of the Nazis and preferred to support the traditional conservative parties instead.
Over the weeks that ensued, most of the remaining inmates of Auschwitz, the largest of the Nazis’ more than 400,000 camps and incarceration facilities, were marched to other camps near and far, walking tens and sometimes even hundreds of miles. Along the way, Beller saw Nazi guards murder prisoners who tried to escape and shoot those who lagged—including women and children so exhausted from starvation and the brutal conditions they could no longer go on. As he marched on, his feet protected by the shoes he’d grabbed before leaving Auschwitz, he saw ordinary Germans standing along the road, watching the prisoners go by.
In May 1943 the SS (Schutzstaffel, "Protective Echelon") announced the removal of all remaining Jews in the Netherlands. In a voluntary call-up on May 25, five hundred Jews voluntarily reported for deportation to Westerbork transit camp. The next day, raids were carried out and 3,000 people were rounded up. Most of these people were sent to the Sobibor extermination camp. About 107,000 Dutch Jews were deported during the war—only about 5,000 returned.
Jerzy Tabeau (prisoner no. 27273, registered as Jerzy Wesołowski) and Roman Cieliczko (no. 27089), both Polish prisoners, escaped on 19 November 1943; Tabeau made contact with the Polish underground and, between December 1943 and early 1944, wrote what became known as the Polish Major's report about the situation in the camp. On 27 April 1944, Rudolf Vrba (no. 44070) and Alfréd Wetzler (no. 29162) escaped to Slovakia, carrying detailed information to the Slovak Jewish Council about the gas chambers. The distribution of the Vrba-Wetzler report, and publication of parts of it in June 1944, helped to halt the deportation of Hungarian Jews to Auschwitz. On 27 May 1944, Arnost Rosin (no. 29858) and Czesław Mordowicz (no. 84216) also escaped to Slovakia; the Rosin-Mordowicz report was added to the Vrba-Wetzler and Tabeau reports to become what is known as the Auschwitz Protocols. The reports were first published in their entirety in November 1944 by the United States War Refugee Board, in a document entitled The Extermination Camps of Auschwitz (Oświęcim) and Birkenau in Upper Silesia.
By 1940, the CCI came under the control of the Verwaltung und Wirtschaftshauptamt Hauptamt (VuWHA; Administration and Business office) which was set up under Oswald Pohl. Then in 1942, the CCI became Amt D (Office D) of the consolidated main office known as the SS-Wirtschafts-Verwaltungshauptamt (SS Economic and Administrative Department; WVHA) under Pohl. In 1942, the SS built a network of extermination camps to systematically kill millions of prisoners by gassing. The extermination camps (Vernichtungslager) and death camps (Todeslager) were camps whose primary function was genocide. The Nazis themselves distinguished the concentration camps from the extermination camps. The British intelligence service had information about the concentration camps, and in 1942 Jan Karski delivered a thorough eyewitness account to the government.