"Rothenburg [a subordinate tank commander] now drove off through a hollow to the left with the five tanks which were to accompany the infantry, thus giving these tanks a lead of 100 to 150 yards. There was no sound of enemy fire. Some 20 to 30 tanks followed up behind. When the commander of the five tanks reached the rifle company on the southern edge of Onhaye wood, Colonel Rothenburg moved off with his leading tanks along the edge of the wood going west. We had just reached the southwest corner of the wood and were about to cross a low plantation, from which we could see the five tanks escorting the infantry below us to our left front, when suddenly we came under heavy artillery and anti-tank gunfire from the west. Shells landed all round us and my tank received two hits one after the other, the first on the upper edge of the turret and the second in the periscope.
The first experimental gassing took place in September 1941, when Lagerführer Karl Fritzsch, at the instruction of Rudolf Höss, killed a group of Soviet prisoners of war by throwing Zyklon B crystals into their basement cell in block 11 of Auschwitz I. A second group of 600 Soviet prisoners of war and around 250 sick Polish prisoners was gassed on 3–5 September.[29] The morgue was later converted to a gas chamber able to hold at least 700–800 people.[30] Zyklon B was dropped into the room through slits in the ceiling.[28] In the view of Filip Müller, one of the Sonderkommando who worked in crematorium I, tens of thousands of Jews were killed there from France, Holland, Slovakia, Upper Silesia, Yugoslavia, and from the Theresienstadt, Ciechanow, and Grodno ghettos.[31] The last inmates to be gassed in Auschwitz I, in December 1942, were 300–400 members of the Auschwitz II Sonderkommando, who had been forced to dig up that camp's mass graves, thought to hold 100,000 corpses, and burn the remains.[32]
In 1914, German strategic thinking derived from the writings of Carl von Clausewitz (June 1, 1780 – November 16, 1831), Helmuth von Moltke the Elder (26 October 1800 – 24 April 1891) and Alfred von Schlieffen (28 February 1833 – 4 January 1913), who advocated manoeuvre, mass and envelopment to create the conditions for a decisive battle (Vernichtungsschlacht). During the war, officers such as Willy Rohr developed tactics to restore manoeuvre on the battlefield. Specialist light infantry (Sturmtruppen, "storm troops") were to exploit weak spots to make gaps for larger infantry units to advance with heavier weapons and exploit the success, leaving isolated strong points to troops following up. Infiltration tactics were combined with short hurricane artillery bombardments using massed artillery, devised by Colonel Georg Bruchmüller. Attacks relied on speed and surprise rather than on weight of numbers. These tactics met with great success in Operation Michael, the spring offensive of 1918 and restored temporarily the war of movement, once the Allied trench system had been overrun. The German armies pushed on towards Amiens and then Paris, coming within 120 kilometres (75 mi) before supply deficiencies and Allied reinforcements halted the advance.[27] Historian James Corum criticised the German leadership for failing to understand the technical advances of the First World War, having given tank production the lowest priority and having conducted no studies of the machine gun prior to that war.[28]
On the Eastern Front, the war did not bog down into trench warfare; German and Russian armies fought a war of manoeuvre over thousands of miles, which gave the German leadership unique experience not available to the trench-bound western Allies.[30] Studies of operations in the east led to the conclusion that small and coordinated forces possessed more combat power than large, uncoordinated forces. After the war, the Reichswehr expanded and improved infiltration tactics. The commander in chief, Hans von Seeckt, argued that there had been an excessive focus on encirclement and emphasized speed instead.[31] Seeckt inspired a revision of Bewegungskrieg (maneuver warfare) thinking and its associated Auftragstaktik, in which the commander expressed his goals to subordinates and gave them discretion in how to achieve them; the governing principle was "the higher the authority, the more general the orders were", so it was the responsibility of the lower echelons to fill in the details.[32] Implementation of higher orders remained within limits determined by the training doctrine of an elite officer-corps.[33] Delegation of authority to local commanders increased the tempo of operations, which had great influence on the success of German armies in the early war period. Seeckt, who believed in the Prussian tradition of mobility, developed the German army into a mobile force, advocating technical advances that would lead to a qualitative improvement of its forces and better coordination between motorized infantry, tanks, and planes.[34]
The Maginot Line: the Allies expected a protracted, defensive war  © Across the English Channel, a stunned British military establishment struggled to determine how it was that events had so quickly gone so horribly wrong. The BEF had sailed for France believing that they and their French ally were well equipped and well trained to fight a modern war. In truth, as events proved, they were completely unprepared to face Hitler's Wehrmacht.
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.