At dawn on September 1, 1939, the German battleship Schleswig-Holstein opened fire on a Polish garrison at Danzig, and 1.5 million German soldiers poured across the Polish frontier. Within hours, dive-bombers were screaming over Warsaw. The war that followed would last almost six years, draw in every great power on earth, and kill somewhere between 60 and 80 million people — soldiers and civilians alike, more of the latter than the former. It would end with two cities vaporized by a single bomb each, with much of Europe in rubble, and with the discovery, as Allied troops opened the camps, of an act of murder so vast and so deliberate that the world needed a new word — genocide — to name it.
This lesson tells two intertwined stories: the military history of the deadliest conflict in human history, and the Holocaust, the systematic, state-organized murder of Europe's Jews. The central questions: How did Hitler's war unfold, why did the Axis lose, and how did a modern, educated European state organize the industrialized killing of millions?
The road to war ran through an alliance no one expected. On August 23, 1939, the two great ideological enemies of Europe — Nazi Germany and the Soviet Union — stunned the world by signing the Nazi–Soviet Pact (the Molotov–Ribbentrop Pact, named for the two foreign ministers). Publicly it was a non-aggression treaty; secretly, a protocol divided Eastern Europe between them, assigning Poland and the Baltic states to German and Soviet "spheres." For Hitler it removed the nightmare of a two-front war; for Stalin it bought time and territory. It cleared the last obstacle to invasion.
On September 1, 1939, Germany invaded Poland. Britain and France, having pledged to defend Poland after the seizure of Czechoslovakia (Lesson 21), declared war on September 3. The era of appeasement was over. On September 17, the Soviet Union invaded Poland from the east, as the secret protocol had arranged. Poland, attacked from both sides, fell in weeks and was partitioned.
Connections (backward): The war is the failure of appeasement made flesh. Each concession from the Rhineland (1936) to Munich (1938) had taught Hitler the West would not fight — until Poland, where it finally did. But the pact with Stalin shows Hitler had learned the lesson too well: he gambled that Britain and France would again do nothing.
Germany's early victories came from Blitzkrieg ("lightning war") — fast, concentrated thrusts of tanks (Panzers), motorized infantry, and air power (the Luftwaffe) that punched through enemy lines and encircled them before they could react. After a quiet winter (the "Phony War"), the storm broke in 1940. Germany overran Denmark and Norway in April, then struck west in May, bypassing France's fortified Maginot Line by driving through the Ardennes forest. The Allied armies were split and routed. In late May and early June, some 338,000 British and French troops were evacuated from the beaches of Dunkirk in a desperate flotilla of ships — a deliverance, but also a catastrophic defeat. France surrendered on June 22, 1940. Hitler had conquered Western Europe in six weeks. A collaborationist French regime was set up at Vichy under Marshal Pétain; the rest was occupied.
Britain now stood alone, under a new prime minister, Winston Churchill (in office from May 10, 1940), who refused all talk of surrender. Hitler needed air supremacy to invade across the Channel, and in the Battle of Britain (July–October 1940) the Royal Air Force fought the Luftwaffe in the skies and won — the first German defeat of the war. Frustrated, Hitler turned to terror bombing of British cities, the Blitz (September 1940–May 1941), which killed some 43,000 civilians but failed to break British morale. The invasion of Britain was postponed, then abandoned.
Hitler's true ambition lay in the east — Lebensraum ("living space") and the destruction of "Judeo-Bolshevism." Tearing up his pact with Stalin, he launched Operation Barbarossa on June 22, 1941: the largest land invasion in history, over 3 million Axis troops along a 1,800-mile front. The Soviets were caught unprepared; the Germans advanced hundreds of miles, besieging Leningrad (a siege that would last 872 days and starve roughly a million people) and threatening Moscow. But the USSR did not collapse. The Soviets traded space for time, the winter froze the unprepared German army, and Soviet industry, evacuated east, began outproducing Germany.
The turning point came at Stalingrad (August 1942–February 1943), a months-long battle of unimaginable savagery in the ruins of a single city. The Soviets encircled the German Sixth Army; after starvation and slaughter, its remnant — about 91,000 men — surrendered on February 2, 1943. Stalingrad was the bloodiest battle of the war and its strategic hinge: from that point the Germans were in retreat in the east, and the Red Army began the long, grinding advance toward Berlin.
Connections (compare): The Eastern Front, not the Western, was where the war in Europe was chiefly decided. Of all German military deaths, roughly three-quarters occurred fighting the Soviets. The USSR suffered some 27 million dead — the heaviest toll of any nation. Remember this when Lesson 23 explains why Stalin felt entitled to dominate Eastern Europe after the war.
The conflict became a true world war on December 7, 1941, when Japan — Germany's ally in the Axis — attacked the U.S. naval base at Pearl Harbor, Hawaii. The United States declared war on Japan; days later, on December 11, 1941, Hitler declared war on the United States. The world's greatest industrial power was now fully committed to the Allied cause. The Grand Alliance — Britain, the Soviet Union, and the United States — was an alliance of necessity binding capitalist democracies to a communist dictatorship against a common enemy. Its industrial might would ultimately overwhelm the Axis.
The Second World War was the cover and the instrument for the Holocaust — the deliberate, systematic, state-organized murder of European Jewry. It must be understood not as a byproduct of war but as a central Nazi war aim, pursued with bureaucratic precision even as Germany lost. Treat it with the gravity it demands.
The genocide escalated in distinct phases. It began with persecution: the Nuremberg Laws (1935) stripped German Jews of citizenship (Lesson 21), and on the night of November 9–10, 1938 — Kristallnacht, the "Night of Broken Glass" — Nazi mobs across Germany and Austria burned synagogues, smashed Jewish shops, killed scores, and dragged some 30,000 Jewish men to concentration camps. Persecution was now open violence.
With the conquest of Poland and then the USSR, millions more Jews fell under Nazi control. The regime herded them into sealed, overcrowded ghettos (the Warsaw Ghetto held over 400,000 people in misery), where disease and starvation killed tens of thousands. Then came the second phase: mass shooting. Behind the advancing armies of Barbarossa came the Einsatzgruppen — mobile killing squads that, with help from the SS, police, and local collaborators, rounded up and shot Jews, communists, and Roma at the edges of pits. At Babi Yar, a ravine outside Kyiv, they murdered 33,771 Jews in two days (September 29–30, 1941). By such methods well over a million people were shot.
The Nazi leadership judged mass shooting too "inefficient" and too psychologically taxing on the killers. At the Wannsee Conference on January 20, 1942, senior officials — chaired by Reinhard Heydrich, with Adolf Eichmann keeping the minutes — coordinated the bureaucracy of what they called the "Final Solution to the Jewish Question": the murder of all of Europe's Jews. This was the third phase: industrialized killing. Across occupied Poland the SS built death camps designed for one purpose — extermination — using poison gas. At Treblinka, Belzec, Sobibor, Chelmno, and the largest, Auschwitz-Birkenau, victims arrived by train, were "selected," and the majority were murdered in gas chambers within hours, their bodies burned in crematoria. At Auschwitz alone, roughly 1.1 million people were killed, the overwhelming majority Jews.
By 1945 the Nazis and their collaborators had murdered approximately six million Jews — two-thirds of Europe's prewar Jewish population — in a genocide unprecedented in its scale, its modernity, and its cold deliberation. Alongside them the regime murdered millions of other victims: Roma (Sinti and Roma), disabled people (killed in the "euthanasia" program), Soviet prisoners of war (some 3 million died in German captivity), Polish civilians and intelligentsia, political prisoners, homosexuals, and Jehovah's Witnesses. The Holocaust was not the work of a few fanatics but of a modern state — its railways, its civil service, its industry, its science — turned to mass murder.
By 1943 the Allies had seized the initiative. After clearing North Africa and invading Italy (which led to Mussolini's fall in 1943), the Western Allies launched the decisive blow in the west: D-Day, the Normandy landings, on June 6, 1944. Under the supreme command of American general Dwight D. Eisenhower, some 156,000 troops crossed the English Channel and stormed the beaches of Nazi-occupied France in the largest seaborne invasion ever attempted. The Allies broke out, liberated Paris in August 1944, and pushed toward Germany from the west while the Red Army drove from the east.
As Soviet troops advanced through Poland, they overran the death camps, liberating Auschwitz on January 27, 1945 (now observed as International Holocaust Remembrance Day). Western forces reached camps such as Bergen-Belsen and Dachau in the spring; the photographs and film of the survivors and the dead seared the reality of the genocide into the world's conscience. Caught between two armies, Germany collapsed. Hitler killed himself in his Berlin bunker on April 30, 1945, and Germany surrendered unconditionally days later — V-E Day (Victory in Europe), May 8, 1945.
The war in the Pacific continued. To force Japan's surrender without a costly invasion, the United States dropped atomic bombs on Hiroshima (August 6, 1945) and Nagasaki (August 9, 1945), killing well over 100,000 people, most of them civilians, and ushering in the nuclear age. Japan surrendered on August 15, 1945 (V-J Day); the formal surrender came on September 2. The Second World War was over.
Even as they fought, the "Big Three" — Churchill, Stalin, and U.S. President Franklin Roosevelt — met to plan victory and the peace. At Tehran (November–December 1943), they agreed to open the western front (D-Day). At Yalta (February 1945), with victory near, they agreed to divide Germany into occupation zones, to establish a new international body, and — in the fateful, ambiguous compromise — that Stalin would permit "free elections" in the Eastern European countries the Red Army was occupying, a promise he had no intention of keeping. By Potsdam (July–August 1945), Roosevelt was dead (succeeded by Harry Truman) and Churchill was voted out mid-conference; the wartime warmth had cooled into suspicion over the fate of Poland and Germany.
Out of the war's catastrophe came one enduring institution of hope: the United Nations, its charter signed in San Francisco on June 26, 1945, designed to succeed where the League of Nations (Lesson 19) had failed in preventing another world war. But the same conferences that founded the UN also drew the lines of the next conflict.
Connections (forward): Yalta's broken promise of "free elections" and the division of Germany and Europe into Soviet and Western zones are the direct origin of the Cold War and the Iron Curtain (Lesson 23). The Grand Alliance dissolved the moment its common enemy was destroyed; the map drawn by the advancing armies in 1945 would divide Europe for the next forty-five years.
Source: Primo Levi, If This Is a Man (published in Italy as Se questo è un uomo, 1947; published in the United States as Survival in Auschwitz). Levi, an Italian Jewish chemist, was deported to Auschwitz in 1944 and survived. These are the opening lines of the poem that prefaces the book. [Authentic and revered. English wording varies by translation — the widely used Stuart Woolf translation is paraphrased/excerpted here; flag exact wording for reviewers and consult a primary edition.]
"You who live safe / In your warm houses, / You who find, returning in the evening, / Hot food and friendly faces: / Consider if this is a man / Who works in the mud, / Who does not know peace, / Who fights for a scrap of bread, / Who dies because of a yes or a no...."
This is the testimony of a survivor of genocide and must be read with the utmost respect — as a moral witness, not a "document" to be coolly mined. Its very purpose is to refuse forgetting.
HAPPY analysis: - Historical context: Written immediately after the war by a survivor of Auschwitz, as Europe began to reckon with the scale of the Holocaust and as some preferred to look away. - Audience: "You who live safe" — the comfortable postwar reader, addressed directly and accusingly, made responsible for remembering. - Purpose: To bear witness; to make the reader consider whether the person reduced to fighting for a scrap of bread is still "a man" — to insist on the humanity the camps tried to erase, and to command remembrance (the poem closes with a charge never to forget). - Point of view: A survivor and a scientist, writing with deliberate restraint rather than rage — which makes the testimony more, not less, devastating. - whY it matters: Primary testimony like Levi's is how we know the Holocaust not only as a statistic — six million — but as the murder of individual human beings, one at a time. The historian's duty is to preserve both the number and the name.
What caused World War II? The AP exam rewards a layered answer: - The failure of appeasement (short-term): the policy of concession (Lesson 21) emboldened Hitler, who concluded the West would never fight, and made the Nazi–Soviet Pact the final green light for invasion. - Unresolved grievances of World War I (long-term): the Treaty of Versailles, the "stab-in-the-back" myth, and German revanchism gave Hitler his cause; an unstable interwar order never reintegrated Germany peacefully. - Fascist aggression and ideology (the driving cause): ultimately the war was willed by Hitler — Lebensraum, racial conquest of the east, and the destruction of the Versailles order were Nazi war aims, not reactions. Mussolini's and Japan's expansionism compounded it. - The weakness of collective security: the League of Nations and the democracies failed to deter aggression in the 1930s (Manchuria, Ethiopia, the Rhineland).
Compare WWII with WWI:
| World War I (1914–1918) | World War II (1939–1945) | |
|---|---|---|
| Character | Stalemate; trench warfare; static fronts | Mobile war; Blitzkrieg, armor, air power |
| Scale of death | ~17 million; mostly soldiers | ~60–80 million; majority civilians |
| Civilians | Affected, but mostly spared deliberate mass killing | Deliberately targeted — bombing, occupation, genocide |
| Ideology | Nationalism, alliances, imperial rivalry | A war of ideologies and racial annihilation |
| Outcome | Punitive peace (Versailles) that bred the next war | Total victory, occupation, a divided Europe, the UN |
The essential difference: WWII was a total war of ideology and extermination, in which the line between soldier and civilian was deliberately erased — and which contained, at its heart, the Holocaust.
The conference order: Tehran → Yalta → Potsdam. Get the chronology and the changing cast right. Tehran (late 1943) — Churchill, Roosevelt, Stalin agree to open the second front. Yalta (February 1945) — same three men, war nearly won, divide Germany and make the doomed "free elections" promise. Potsdam (July–August 1945) — Germany already defeated; Roosevelt is dead (Truman now President) and Churchill is replaced mid-conference by Attlee. A useful mnemonic: the alliance was warmest at Tehran and coldest at Potsdam, where the Cold War was already dawning. Don't put Yalta after Potsdam.
The Eastern Front vs. the Western Front. The Eastern Front (Germany vs. the USSR, from June 1941) was by far the larger and bloodier theater, decided at Stalingrad and Kursk; the Western Front opened decisively with D-Day (June 1944). Students sometimes imagine the U.S. and Britain "won the war" alone; in fact the Red Army broke the bulk of the German army. Both fronts mattered, but don't shrink the Eastern Front.
The three phases of the Holocaust. The genocide was not a single event but an escalation: (1) persecution (Nuremberg Laws 1935, Kristallnacht 1938) — exclusion and legal stripping of rights; (2) mass shooting (the Einsatzgruppen, from 1941, e.g. Babi Yar); (3) industrialized killing in death camps after the Wannsee Conference (January 1942). Confusing these phases — or treating the Holocaust as if it began with the camps — misses how a state moved, step by step, from discrimination to genocide. Also: do not confuse concentration camps (imprisonment, forced labor) with death/extermination camps (built for immediate mass murder, e.g. Treblinka); Auschwitz contained both.
Stimulus for Questions 13–14. Study the following description of a map of Europe in late 1942 (at the height of Axis expansion).
The map shades German-controlled territory at its greatest extent: it stretches from the Atlantic coast of France in the west to deep inside the Soviet Union in the east — past Kyiv, to the gates of Stalingrad on the Volga and into the Caucasus. Norway, Denmark, the Low Countries, Poland, and the Balkans are shaded as occupied or allied. Britain (unshaded) stands apart across the Channel; neutral Sweden, Switzerland, Spain, and Portugal are unshaded. A front line is marked deep inside Soviet territory.
Stimulus for Questions 15–16. Read the excerpt, the testimony of a Holocaust survivor, presented here with respect as a moral witness.
"You who live safe / In your warm houses... / Consider if this is a man / Who works in the mud, / Who does not know peace, / Who fights for a scrap of bread, / Who dies because of a yes or a no." — Primo Levi, If This Is a Man (1947), prefatory poem [authentic; English translation wording varies — verify against a primary edition]
SAQ Rubric (3 points total) — see section (g). Award 1 point per part: (a) identifies a specific, accurate 1940 circumstance (fall of France, Dunkirk, Britain standing alone facing invasion); (b) explains a specific 1941–1943 development that turned the war against Germany (the failure of Barbarossa, Stalingrad, or Pearl Harbor/U.S. entry) — identification plus explanation of how it shifted the war; (c) explains a specific consequence of the war's outcome for postwar Europe (the Cold War division and Soviet domination of Eastern Europe via Yalta and Red Army occupation, or the founding of the United Nations). Parts are scored independently. The most common failures are vagueness, naming a term without explaining it, and straying outside the stated time frame in part (b).
Use the passage below to answer parts (a), (b), and (c).
"We shall go on to the end... we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our Island, whatever the cost may be, we shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender." — Winston Churchill, speech to the House of Commons, June 4, 1940 [authentic; widely documented — verify exact wording against the Hansard parliamentary record]
(a) Identify ONE historical circumstance in 1940 that explains why Churchill delivered this speech. (b) Explain ONE development in the war between 1941 and 1943 that shifted the conflict against Germany. (c) Explain ONE way the outcome of World War II shaped the postwar order in Europe.
(This is a primary-source SAQ. On the real exam you would have roughly 12–13 minutes for a three-part question. Each part is worth 1 point. Write in complete sentences; you do not need a thesis or an introduction — answer each part directly and specifically.)
(a) In May–June 1940, Germany's Blitzkrieg had overrun Western Europe: France was collapsing (it surrendered on June 22), and the British army had just been evacuated from Dunkirk, leaving Britain standing alone against Nazi Germany and facing the threat of invasion. Churchill spoke to steel British resolve to fight on rather than seek terms.
(b) Two developments turned the war: the German invasion of the Soviet Union (Operation Barbarossa, June 1941) failed to defeat the USSR and bogged down, and the German Sixth Army was encircled and forced to surrender at Stalingrad in February 1943, beginning the German retreat on the Eastern Front. (Pearl Harbor in December 1941, which brought the industrial power of the United States into the war, is an equally valid answer.)
(c) The defeat of Germany left the Red Army occupying Eastern Europe, and the wartime agreements at Yalta divided Germany and Europe into Soviet and Western zones; Stalin's refusal to honor the promise of free elections led to Soviet domination of Eastern Europe and the division of the continent in the Cold War. (The founding of the United Nations in 1945 to preserve peace is also acceptable.)
| Part | Point earned for... | Why the model earns it |
|---|---|---|
| (a) | A specific, accurate 1940 circumstance | Names the fall of France / Dunkirk / Britain standing alone facing invasion — directly explains the speech. |
| (b) | A specific development from 1941–1943 that turned the war, explained | Barbarossa's failure / Stalingrad (or Pearl Harbor) — and states how it shifted the war against Germany, not just that it happened. |
| (c) | A specific consequence for postwar Europe, explained | Connects the war's outcome to the Cold War division (Yalta, Soviet occupation) or the UN — a clear cause-and-effect link. |
Each part stands alone; a wrong answer in one part does not cost points in another. Parts (b) and (c) ask you to explain, so a bare term ("Stalingrad") is weaker than a sentence that states the consequence ("...which began the German retreat in the east").
MCQ Solutions
SAQ Rubric (3 points total) — see section (g). Award 1 point per part: (a) identifies a specific, accurate 1940 circumstance (fall of France, Dunkirk, Britain standing alone facing invasion); (b) explains a specific 1941–1943 development that turned the war against Germany (the failure of Barbarossa, Stalingrad, or Pearl Harbor/U.S. entry) — identification plus explanation of how it shifted the war; (c) explains a specific consequence of the war's outcome for postwar Europe (the Cold War division and Soviet domination of Eastern Europe via Yalta and Red Army occupation, or the founding of the United Nations). Parts are scored independently. The most common failures are vagueness, naming a term without explaining it, and straying outside the stated time frame in part (b).
EuroIQ · Lesson 22 of 25 · Period 4 · Unit 8: World War II and the Holocaust
This lesson is exam-prep study material aligned to the AP® European History Course and Exam Description. AP® is a trademark registered by the College Board, which is not affiliated with and does not endorse this product. The Holocaust is presented here as the systematic, state-organized genocide it was — the murder of approximately six million Jews, alongside millions of Roma, disabled people, Soviet prisoners of war, Polish civilians, political prisoners, and others — and is treated with gravity and historical precision; it is never minimized, sensationalized, or relativized. Survivor testimony is quoted with respect, as moral witness. Dates, figures, attributions, and translations are drawn from standard scholarly sources; readers should consult primary editions for exact wording.
Content pending external history review.