Mastering Depth study E: The Second World War in Europe and the Asia-Pacific, 1939-c.1945: IGCSE History Study Notes

What this depth study demands from you

Depth Study E tests whether you can do more than list dates and battles. The IGCSE mark scheme rewards cause-effect reasoning, balanced evaluation, and specific factual support. You need to explain why events happened, why they mattered, and how they connected. Every paragraph you write in the exam should advance an argument, not repeat a fact. This guide gives you the knowledge base and the analytical tools to do exactly that across all four topics.

Topic 1: How did the Second World War in Europe develop?

Blitzkrieg and the fall of Western Europe (1939-40)

Germany invaded Poland on 1 September 1939 using Blitzkrieg (lightning war): fast-moving tanks supported by dive-bombers and motorised infantry punching through enemy lines before defenders could regroup. Poland fell in five weeks. The speed was the point. Blitzkrieg relied on concentrated armoured thrusts, close air support, and encirclement of enemy forces. Static defence lines became obsolete overnight.

In April-June 1940, Germany swept through Denmark, Norway, the Netherlands, Belgium, and France. The critical blow came through the Ardennes forest, which the French considered impassable for tanks. German armour bypassed the Maginot Line entirely, split the Allied forces, and trapped the British Expeditionary Force at Dunkirk. Over 338,000 troops were evacuated across the Channel (Operation Dynamo, 26 May - 4 June 1940), but France signed an armistice on 22 June. By mid-1940, Nazi Germany controlled most of Western Europe.

The Battle of Britain (1940)

Hitler needed air superiority before any Channel crossing. The Luftwaffe attacked RAF airfields and radar stations from July 1940. Britain was close to breaking point by early September. Then Germany switched to bombing London (the Blitz), giving the RAF time to recover. This tactical error was decisive. British advantages included radar, the home advantage of short flying distances, and the Spitfire and Hurricane fighters. Germany never achieved air superiority. Operation Sea Lion (the planned invasion) was postponed indefinitely.

Why could Germany not conquer Britain? Three factors. First, the Royal Navy controlled the Channel. Second, the RAF denied the Luftwaffe air supremacy. Third, Britain had strategic depth: an island with Atlantic supply lines that Germany could harass but not sever in 1940.

Operation Barbarossa and the Eastern Front (1941-43)

Hitler invaded the Soviet Union on 22 June 1941 with over three million troops. His reasons: ideological hatred of communism, desire for Lebensraum (living space) in the east, and the belief that the Red Army was weak after Stalin's purges of the officer corps. Initial German advances were spectacular. By October 1941, the Wehrmacht was within sight of Moscow.

Three factors stalled the invasion. The vast distances stretched supply lines. The autumn rains turned roads to mud (the rasputitsa). The early and brutal Russian winter caught German troops without adequate clothing or equipment. The Soviets traded space for time, relocated factories east of the Urals, and mobilised reserves. Moscow held.

Stalingrad: the turning point (1942-43)

The Battle of Stalingrad (August 1942 - February 1943) was the decisive moment on the Eastern Front. Hitler targeted the city for its strategic position on the Volga and its symbolic value (it bore Stalin's name). The German Sixth Army under Paulus fought street by street but could not take the entire city. In November 1942, the Soviet Operation Uranus encircled the Sixth Army. Hitler refused to allow a breakout. On 2 February 1943, Paulus surrendered with roughly 91,000 surviving troops.

Stalingrad was a turning point for identifiable reasons. It destroyed an entire German army. It proved the Wehrmacht could be beaten in a major battle. It shifted the strategic initiative to the Soviets, who began pushing westward and never stopped. After Stalingrad, Germany was fighting a defensive war in the east.

D-Day and the fall of Berlin (1944-45)

The Allied invasion of Normandy on 6 June 1944 (D-Day) opened a second front in Western Europe. Over 156,000 troops landed on five beaches. Success depended on deception (Operation Fortitude convinced Germany the main attack would hit Calais), air superiority, and overwhelming naval firepower. Paris was liberated in August 1944. The Allies pushed into Germany from the west while the Soviets advanced from the east. Hitler committed suicide on 30 April 1945. Germany surrendered unconditionally on 8 May 1945 (VE Day).

Topic 2: How did the Second World War in the Asia-Pacific develop?

US-Japanese tensions before Pearl Harbor

Japan's expansion into China (from 1937) and Southeast Asia put it on a collision course with the United States. The cause-effect chain is straightforward. Japan needed oil, rubber, and raw materials to sustain its war in China. The US imposed trade embargoes, freezing Japanese assets and cutting off oil supplies in July 1941. Japan faced a choice: abandon its empire or seize the resource-rich territories of Southeast Asia by force. Seizing those territories meant war with America.

Pearl Harbor and Japanese conquests (1941-42)

On 7 December 1941, Japan attacked the US Pacific Fleet at Pearl Harbor, Hawaii. The strike sank or damaged eight battleships and killed over 2,400 Americans. Japan's aim was to cripple the US fleet long enough to build a defensive perimeter across the Pacific. The attack brought America into the war with overwhelming public support.

Within six months, Japan conquered the Philippines, Malaya, Singapore, the Dutch East Indies (Indonesia), and Burma. The fall of Singapore (15 February 1942), where roughly 80,000 British and Commonwealth troops surrendered, was the largest British military capitulation in history. Japan's victories rested on speed, air power, and the element of surprise against forces that were spread thin and poorly coordinated.

Midway: the Pacific turning point (June 1942)

The Battle of Midway (4-7 June 1942) turned the Pacific war. US codebreakers identified Midway atoll as the Japanese target. American carrier-based aircraft sank four Japanese fleet carriers in a single day. Japan lost its offensive naval capability and never recovered it. From Midway onward, America held the strategic initiative.

Island-hopping, Burma, and the road to Japan (1943-45)

The US adopted an island-hopping strategy: bypassing heavily fortified Japanese garrisons to seize islands closer to Japan, cutting off the bypassed garrisons from supply. Key battles included Guadalcanal (1942-43), Saipan (1944), Iwo Jima (February-March 1945), and Okinawa (April-June 1945). Each island brought American bombers closer to the Japanese mainland. Japanese resistance was fanatical; soldiers fought to the death, and kamikaze pilots deliberately crashed into Allied ships.

In Burma, British and Commonwealth forces (including Gurkhas and troops from India and Africa) fought in brutal jungle conditions. The Japanese sieges at Imphal and Kohima (March-July 1944) were defeated, and the reconquest of Burma followed. This campaign is often overlooked in exam answers but was significant for breaking Japanese power in Southeast Asia.

The atomic bombs (August 1945)

The US dropped an atomic bomb on Hiroshima on 6 August 1945 and on Nagasaki on 9 August 1945. Hiroshima killed an estimated 80,000 people instantly, with tens of thousands more dying from radiation. Japan surrendered on 15 August 1945 (VJ Day). The decision to use the bombs remains one of the most debated questions of the war. Proponents argued it ended the war quickly and avoided a land invasion of Japan that could have cost hundreds of thousands of casualties on both sides. Critics argued Japan was already close to surrender, and the bombs were unnecessary or were partly motivated by demonstrating power to the Soviet Union.

Topic 3: What was the impact of war on civilian populations?

The Blitz and strategic bombing in Europe

German bombing of British cities (the Blitz, September 1940 - May 1941) killed approximately 43,000 civilians and destroyed large areas of London, Coventry, and other cities. The British government responded with evacuation of children, blackouts, air-raid shelters, and rationing. Civilian morale was tested but did not collapse.

Allied strategic bombing of Germany escalated from 1942. The bombing of Hamburg (Operation Gomorrah, July 1943) created a firestorm that killed an estimated 37,000 people. The bombing of Dresden (February 1945) killed approximately 25,000 civilians and remains controversial because the city had limited military significance by that stage of the war. Strategic bombing aimed to destroy Germany's industrial capacity and break civilian morale. It achieved the first objective partially but never achieved the second.

The Holocaust

The Nazi regime systematically murdered approximately six million Jews, along with Roma, disabled people, homosexuals, political opponents, and others deemed "undesirable." The process escalated in stages: legal discrimination (Nuremberg Laws, 1935), organised violence (Kristallnacht, 1938), ghettoisation (Warsaw Ghetto, 1940), mass shootings by Einsatzgruppen on the Eastern Front (from 1941), and industrialised killing in extermination camps (Auschwitz-Birkenau, Treblinka, Sobibor, from 1942). The Wannsee Conference (January 1942) coordinated the "Final Solution" across occupied Europe.

For IGCSE purposes, understand the escalation pattern: each stage removed a barrier that made the next stage possible. Legal exclusion normalised treating Jews as outsiders. Ghettoisation concentrated populations. The cover of war on the Eastern Front enabled mass killing far from public scrutiny. The camps industrialised the process.

Occupation and resistance

German occupation across Europe varied in severity. Western Europe experienced economic exploitation, forced labour, and political repression. Eastern Europe and the Soviet Union suffered deliberate starvation policies, mass executions, and the destruction of entire communities. Japanese occupation of Southeast Asia and China involved forced labour (the Burma Railway killed an estimated 12,000 Allied prisoners and over 80,000 Asian labourers), the Nanjing Massacre, and brutal treatment of prisoners of war.

Resistance movements operated across occupied Europe. The French Resistance provided intelligence to the Allies and sabotaged German communications before D-Day. Yugoslav partisans under Tito fought a sustained guerrilla war. The Warsaw Ghetto Uprising (April-May 1943) and the Warsaw Uprising (August-October 1944) demonstrated civilian determination despite overwhelming odds. Resistance was dangerous and often met with savage reprisals against civilian populations.

Atomic destruction in Japan

Beyond the immediate death toll, the atomic bombs produced radiation sickness that killed thousands in the weeks and months that followed. Survivors (hibakusha) suffered long-term health effects including cancer. The firebombing of Tokyo (March 1945) had already killed an estimated 80,000-100,000 civilians in a single night, demonstrating that conventional bombing could be equally devastating. The atomic bombs, however, represented a qualitative leap: a single weapon could destroy an entire city.

Topic 4: How did the Allies achieve victory over the Axis powers?

The three decisive turning points

All three turning points occurred within an eight-month window (June 1942 - February 1943). This is not a coincidence. By mid-1942, the Axis powers had reached the limits of their offensive reach, while Allied industrial and military mobilisation was accelerating. The pattern across all three theatres was the same: an overextended Axis force met a strengthening Allied defence.

Allied cooperation

The Grand Alliance (Britain, the USA, and the USSR) held together despite deep ideological differences. Key agreements shaped the war's direction. The Atlantic Charter (August 1941) established Anglo-American war aims before the US even entered the war. The Tehran Conference (November 1943) committed the Allies to a second front in France. The Yalta Conference (February 1945) divided post-war Germany into occupation zones and established the framework for the United Nations.

Allied cooperation was practical, not sentimental. The USSR bore the heaviest burden on land (an estimated 27 million Soviet dead). The US provided Lend-Lease supplies to both Britain and the USSR. Britain contributed naval power, intelligence (Ultra codebreaking at Bletchley Park), and the base for the D-Day invasion. Each ally needed the others.

Reasons for Axis defeat

Use this checklist for exam answers on why the Axis lost.

• Overextension. Germany fought on two fronts simultaneously (Eastern and Western). Japan stretched across the Pacific with supply lines it could not protect.
• Industrial imbalance. The combined industrial output of the USA, USSR, and Britain dwarfed that of Germany and Japan. The US alone produced nearly 300,000 aircraft during the war.
• Strategic errors. Hitler's refusal to allow retreats (Stalingrad, Normandy) destroyed armies that could have been saved. Japan's attack on Pearl Harbor united American public opinion.
• Allied cooperation. Despite tensions, the Grand Alliance coordinated strategy effectively. The Axis powers did not: Germany and Japan fought essentially separate wars with no joint planning.
• Technology and intelligence. Ultra codebreaking gave the Allies access to German communications. US codebreaking enabled the victory at Midway. Radar, the proximity fuse, and eventually the atomic bomb provided decisive advantages.

Do/Don't table for Depth Study E exam answers

Self-check questions

1. Explain two reasons why Germany was unable to conquer Britain in 1940.
2. Why did Hitler invade the Soviet Union, and what factors caused the invasion to stall?
3. "The Battle of Stalingrad was the most important turning point of the Second World War." How far do you agree? Compare it with at least one other turning point.
4. Explain why US-Japanese relations deteriorated between 1937 and 1941, tracing the cause-effect chain from Japanese expansion to Pearl Harbor.
5. Describe the stages of the Holocaust and explain how each stage made the next possible.
6. Identify three reasons why the Axis powers lost the war and evaluate which was most significant.
7. What role did Allied cooperation play in achieving victory? Consider both its strengths and its tensions.