When Germany invaded Poland, German officials set up a research project into the possible military uses of uranium fission. A nuclear reactor, what the Germans called a “uranium machine,” needed a moderator to slow down neutrons. Water, heavy water, and pure carbon in the form of graphite were all considered, but water would need uranium in which the percentage of isotope 235 is increased, and it did not appear feasible for German industry to produce graphite with sufficient purity. Paul Harteck and his collaborator Wilhelm Groth first tried to separate the uranium isotopes with a separation tube. When this failed, the two physical chemists turned to centrifuges. Scientists in Berlin, Heidelberg, and Leipzig began experiments on the behavior of materials when bombarded with neutrons and on model nuclear reactors. At first the materials needed were scarce but Germany captured the Norsk Hydro in Norway, the largest heavy water producer in the world, and the defeat of Belgium brought with it tons of uranium compounds. From the start of the war through to the autumn of 1941, this research had low priority and made modest progress. At this stage of the war, powerful new weapons did not appear needed.

Chapter 3 discusses the war from the attack on Poland in 1939 to the invasion of Norway, the Low Countries, and France in 1940, and Yugoslavia and Greece in 1941. Chaplains accompanied Wehrmacht units wherever they went, and this period of Blitzkrieg, rapid German victories, proved formative for them. Germany’s conquests opened up new territory for chaplains, who seized the opportunities to assert their loyalty and prove their worth. They gained an enormous audience of soldiers and also ministered to Christian populations in conquered and occupied territories. Chaplains witnessed and got used to German attacks on civilians, such as terror bombings in the Netherlands, shooting of prisoners in Norway, and rampant abuse of Jews and destruction of Jewish sites in Poland. This chapter makes extensive use of chaplains’ periodic reports, submitted up the chain of command. A surprising number of reports refer to chaplains ministering to German soldiers condemned to death by military authorities. The Wehrmacht chaplains projected an image as heroic, battle-hardened men who strengthened the resolve of the troops and built bridges to the homefront, for instance by providing Christian burials.

Chapter 1, “Warsaw Besieged: September 1939,” describes the September 1939 siege of Warsaw during Case White (the September Campaign or Polish Defensive War) by the German Wehrmacht and Nazi SS personnel and the city’s eventual capitulation. The first of four chapters on how Nazi Germany dismantled the Polish state and nation for long-term occupation by targeting the Warsaw intelligentsia, the description of the siege frames the project. The military invasion revealed German brutality and weak Polish military performance, and provoked a Polish government evacuation crisis. The evacuation created chaos, ruptured Poles’ faith in their government, and triggered the creation of a Polish government-in-exile in western Europe far from occupied Warsaw. The people of Warsaw, led by Mayor Stefan Starzyński, coordinated military-civilian cooperative defense efforts, setting the tone for elite behavior during the coming occupation. This chapter argues that the siege-time cooperation was the foundational experience of the capital’s intelligentsia, and framed responses to the persecutions of the coming occupation.

This chapter deals with the early stages of World War II in Europe, which was to some extent a repetition of World War I, but with a German victory in May-June 1940. Allied and German grand strategy. The Soviet-Finnish war. Russian annexation of the three Baltic states. The German invasion of neutral Norway, with naval and ground battles against the Allied forces. Churchill replaces Chamberlain as Prime Minister. Planning on both sides for the main Western Front in 1940. The German Blitzkrieg invasion of France and the Low Countries. The Allied evacuation of Dunkirk, the second phase of the invasion, and the French surrender. Air battle over Britain. Inability of the German Army to invade Britain, and Hitler’s decision to invade Russia.

This chapter deals with the beginnings of World War II in Europe: the revision of the the 1919 Versailles Treaty by Nazi Germany, culminating in the invasion of Poland in September 1939 and the renewal of war with Britain and France. Hitler takes power. Beginning of German rearmament in violation of 1919 Versailles Treaty, including remilitarisation of the Rhineland. Rapid development of the German armed forces (Wehrmacht), including creation of Panzer forces in the army. The Luftwaffe as a powerful threat in the pre-war crises. The French and British armed forces. Mussolini’s invasion of Abyssinia, and strengthening relations with Germany. Russian and American detachment from the pre-war crises. The 1938 Sudeten (Munich) crisis and the partition of Czechoslovakia. Hitler’s plans for war with Poland and the Nazi-Soviet Pact of August 1939. France and Britain declare war. The German invasion, and the rapid overthrow of Poland. The start of war: comparisons between Europe and mainland Asia.