In the 1930s, the political landscape of Europe changed dramatically with the rise of Adolf Hitler and the German Nazi Party. Sensing the shift in political momentum, Schindler joined a local pro-Nazi organization and began collecting intelligence for the German military. He was arrested by Czech authorities in 1938, charged with spying and sentenced to death but was released shortly thereafter, when Germany annexed the Sudetenland. Schindler would take advantage of this second chance.
The photo above shows the gate house which is the main entrance into Birkenau, also known as the Auschwitz II concentration camp. Beginning around the middle of May 1944, freight trains that were 40 to 50 cars long rolled through this gate, day and night, bringing thousands of Hungarian Jews to be gassed at the four Birkenau gas chambers. The prisoners called it the "Gate of Death."

After 1942, the economic functions of the camps, previously secondary to their penal and terror functions, came to the fore. Forced labor of camp prisoners became commonplace.[182] The guards became much more brutal, and the death rate increased as the guards not only beat and starved prisoners, but killed them more frequently.[186] Vernichtung durch Arbeit ("extermination through labor") was a policy—camp inmates would literally be worked to death, or to physical exhaustion, at which point they would be gassed or shot.[187] The Germans estimated the average prisoner's lifespan in a concentration camp at three months, due to lack of food and clothing, constant epidemics, and frequent punishments for the most minor transgressions.[188] The shifts were long and often involved exposure to dangerous materials.[189]
Throughout German-occupied territory the situation of the Jews was desperate. They had meagre resources and few allies and faced impossible choices. A few people came to their rescue, often at the risk of their own lives. Swedish diplomat Raoul Wallenberg arrived in Budapest on July 9, 1944, in an effort to save Hungary’s sole remaining Jewish community. Over the next six months, he worked with other neutral diplomats, the Vatican, and Jews themselves to prevent the deportation of these last Jews. Elsewhere, Le Chambon-sur-Lignon, a French Huguenot village, became a haven for 5,000 Jews. In German-occupied Poland, where it was illegal to aid Jews and where such action was punishable by death, the Zegota (Council for Aid to Jews) rescued a similar number of Jewish men, women, and children. Financed by the London-based Polish government in exile and involving a wide range of clandestine political organizations, Zegota provided hiding places and financial support and forged identity documents.
Jewish deportees arriving at Auschwitz-Birkenau immediately underwent selection. The SS staff chose some of the able-bodied for forced labor and sent the rest directly to the gas chambers, which were disguised as shower installations to mislead the victims. The belongings of all deportees were confiscated and sorted in the "Kanada" (Canada) warehouse for shipment back to Germany. Canada symbolized wealth to the prisoners.
During the interwar period, aircraft and tank technologies matured and were combined with systematic application of the traditional German tactic of Bewegungskrieg (maneuver warfare), deep penetrations and the bypassing of enemy strong points to encircle and destroy enemy forces in a Kesselschlacht (cauldron battle).[3][6] During the Invasion of Poland, Western journalists adopted the term blitzkrieg to describe this form of armoured warfare.[7] The term had appeared in 1935, in a German military periodical Deutsche Wehr (German Defence), in connection to quick or lightning warfare.[8] German manoeuvre operations were successful in the campaigns of 1939–1941 and by 1940 the term blitzkrieg was extensively used in Western media.[9][10] Blitzkrieg operations capitalized on surprise penetrations (e.g., the penetration of the Ardennes forest region), general enemy unreadiness and their inability to match the pace of the German attack. During the Battle of France, the French made attempts to re-form defensive lines along rivers but were frustrated when German forces arrived first and pressed on.[10]
In addition to workers, Schindler moved 250 wagon loads of machinery and raw materials to the new factory.[68] Few if any useful artillery shells were produced at the plant. When officials from the Armaments Ministry questioned the factory's low output, Schindler bought finished goods on the black market and resold them as his own.[69] The rations provided by the SS were insufficient to meet the needs of the workers, so Schindler spent most of his time in Kraków, obtaining food, armaments, and other materials. His wife Emilie remained in Brünnlitz, surreptitiously obtaining additional rations and caring for the workers' health and other basic needs.[70][71] Schindler also arranged for the transfer of as many as 3,000 Jewish women out of Auschwitz to small textiles plants in the Sudetenland in an effort to increase their chances of surviving the war.[72][73]
Hitler was obsessed with the idea of the superiority of the “pure” German race, which he called “Aryan,” and with the need for “Lebensraum,” or living space, for that race to expand. In the decade after he was released from prison, Hitler took advantage of the weakness of his rivals to enhance his party’s status and rise from obscurity to power. On January 30, 1933, he was named chancellor of Germany. After President Paul von Hindenburg’s death in 1934, Hitler anointed himself as “Fuhrer,” becoming Germany’s supreme ruler.
By the end of September, the SS had started to develop plans to deport Jews to newly invaded Poland: the first steps towards the systematic murder that would follow. In Poland itself, thousands of Poles and Jews were rounded up and shot, early indications of the systematic murder that would follow. Alongside this, Hitler approved a new programme of euthanasia to exterminate the handicapped and mentally ill.
As in the concentration camps, those prisoners selected for work faced appalling conditions and severe treatment. After being woken at dawn, they would have to stand in line for the roll call and endure many hours of hard labour. At the end of the working day, exhausted, they returned to the camp, when they would once again have to stand in line for evening roll call.
After Germany invaded Poland in September 1939, sparking World War II, the Germans converted Auschwitz I from an army barracks to hold Polish political prisoners.[3] The first prisoners, German criminals brought to the camp as functionaries, arrived in May 1940,[4] and the first gassing of prisoners took place in block 11 of Auschwitz I in September 1941. Auschwitz II–Birkenau went on to become a major site of the Nazis' Final Solution to the Jewish Question. From early 1942 until late 1944, transport trains delivered Jews from all over German-occupied Europe to the camp's gas chambers. Of the estimated 1.3 million people sent to Auschwitz, at least 1.1 million died,[5] around 90 percent of them Jews.[6] Approximately one in six Jews killed in the Holocaust died at the camp.[7] Others deported to Auschwitz included 150,000 non-Jewish Poles, 23,000 Roma, 15,000 Soviet prisoners of war, 400 Jehovah's Witnesses, tens of thousands of others of diverse nationalities, and an unknown number of gay men. Many of those not killed in the gas chambers died because of starvation, forced labor, infectious diseases, individual executions, and medical experiments.

The German offensive to capture Stalingrad began in August 1942, using the 6th Army and elements of the 4th Panzer Army. The attack was supported by intensive Luftwaffe bombing that reduced much of the city to rubble. The fighting degenerated into house-to-house fighting; both sides poured reinforcements into the city. By mid-November 1942, the Germans had pushed the Soviet defenders back at great cost into narrow zones along the west bank of the Volga River.

Directive control was a fast and flexible method of command. Rather than receiving an explicit order, a commander would be told of his superior's intent and the role which his unit was to fill in this concept. The exact method of execution was then a matter for the low-level commander to determine as best fit the situation. Staff burden was reduced at the top and spread among commands more knowledgeable about their own situation. In addition, the encouragement of initiative at all levels aided implementation. As a result, significant decisions could be effected quickly and either verbally or with written orders a few pages in length.

In early 1942 the Nazis built killing centres at Treblinka, Sobibor, and Belzec in occupied Poland. The death camps were to be the essential instrument of the “final solution.” The Einsatzgruppen had traveled to kill their victims. With the killing centres, the process was reversed. The victims were taken by train, often in cattle cars, to their killers. The extermination camps became factories producing corpses, effectively and efficiently, at minimal physical and psychological cost to German personnel. Assisted by Ukrainian and Latvian collaborators and prisoners of war, a few Germans could kill tens of thousands of prisoners each month. At Chelmno, the first of the extermination camps, the Nazis used mobile gas vans. Elsewhere they built permanent gas chambers linked to the crematoria where bodies were burned. Carbon monoxide was the gas of choice at most camps. Zyklon-B, an especially lethal killing agent, was employed primarily at Auschwitz and later at Majdanek.
German military history had been influenced heavily by Carl von Clausewitz, Alfred von Schlieffen and von Moltke the Elder, who were proponents of maneuver, mass, and envelopment. Their concepts were employed in the successful Franco-Prussian War and attempted "knock-out blow" of the Schlieffen Plan. Following the war, these concepts were modified by the Reichswehr. Its Chief of Staff, Hans von Seeckt, moved doctrine away from what he argued was an excessive focus on encirclement towards one based on speed. Speed gives surprise, surprise allows exploitation if decisions can be reached quickly and mobility gives flexibility and speed. Von Seeckt advocated effecting breakthroughs against the enemy's centre when it was more profitable than encirclement or where encirclement was not practical. Under his command a modern update of the doctrinal system called "Bewegungskrieg" and its associated tactical system called " Auftragstaktik" was developed which resulted in the popularly known blitzkrieg effect. He additionally rejected the notion of mass which von Schlieffen and von Moltke had advocated. While reserves had comprised up to four-tenths of German forces in pre-war campaigns, von Seeckt sought the creation of a small, professional (volunteer) military backed by a defense-oriented militia. In modern warfare, he argued, such a force was more capable of offensive action, faster to ready, and less expensive to equip with more modern weapons. The Reichswehr was forced to adopt a small and professional army quite aside from any German plans, for the Treaty of Versailles limited it to 100,000 men.

The origin of the term blitzkrieg is obscure. It was never used in the title of a military doctrine or handbook of the German army or air force,[9] and no "coherent doctrine" or "unifying concept of blitzkrieg" existed.[20] The term seems rarely to have been used in the German military press before 1939 and recent research at the German Militärgeschichtliches Forschungsamt at Potsdam found it in only two military articles from the 1930s. Both used the term to mean a swift strategic knock-out, rather than a radical new military doctrine or approach to war. The first article (1935) deals primarily with supplies of food and materiel in wartime. The term blitzkrieg is used with reference to German efforts to win a quick victory in the First World War but is not associated with the use of armoured, mechanised or air forces. It argued that Germany must develop self-sufficiency in food, because it might again prove impossible to deal a swift knock-out to its enemies, leading to a long war.[21] In the second article (1938), launching a swift strategic knock-out is described as an attractive idea for Germany but difficult to achieve on land under modern conditions (especially against systems of fortification like the Maginot Line), unless an exceptionally high degree of surprise could be achieved. The author vaguely suggests that a massive strategic air attack might hold out better prospects but the topic is not explored in detail. A third relatively early use of the term in German occurs in Die Deutsche Kriegsstärke (German War Strength) by Fritz Sternberg, a Jewish, Marxist, political economist and refugee from the Third Reich, published in 1938 in Paris and in London as Germany and a Lightning War. Sternberg wrote that Germany was not prepared economically for a long war but might win a quick war ("Blitzkrieg"). He did not go into detail about tactics or suggest that the German armed forces had evolved a radically new operational method. His book offers scant clues as to how German lightning victories might be won.[21]

His tasks for the Abwehr included collecting information on railways, military installations, and troop movements, as well as recruiting other spies within Czechoslovakia, in advance of a planned invasion of the country by Nazi Germany.[9] He was arrested by the Czech government for espionage on 18 July 1938 and immediately imprisoned, but was released as a political prisoner under the terms of the Munich Agreement, the instrument under which the Czech Sudetenland was annexed into Germany on 1 October.[10][11] Schindler applied for membership in the Nazi Party on 1 November and was accepted the following year.[12]