20th-Century Global Conflicts

What this unit covers

The topics below follow the published Euro History course framework for Unit 8. This unit is worth 10–15% of the exam, so budget your time against that rather than against how long the unit takes to teach.

Lessons in this unit

• World War I15 min · 3 objectivesAnalyze the long-term and immediate causes of World War I · Explain how new technology produced total war and stalemate · Evaluate the terms and consequences of the Treaty of Versailles
• Russian Revolution, Depression & the Rise of Dictators15 min · 3 objectivesExplain the causes and outcome of the Russian Revolution · Analyze the impact of the Great Depression on European politics · Compare the features of fascist and communist totalitarian regimes
• World War II & the Holocaust15 min · 3 objectivesExplain how appeasement and aggression led to World War II · Describe the global scope and turning points of the war · Analyze the Holocaust as an act of state-sponsored genocide
• Alliances, Militarism & the July Crisis14 min · 3 objectivesExplain how the alliance system turned a local dispute into a continental war · Analyze the role of military planning and mobilization timetables · Weigh competing explanations for the outbreak of war in 1914
• Total War: Economies, Women & Propaganda, 1914–194513 min · 3 objectivesDefine total war and identify its characteristic features · Assess the effect of both wars on women’s work and political rights · Explain how states used propaganda and censorship to sustain mass mobilization

Every term in Unit 8

All 35 terms we publish for 20th-Century Global Conflicts, with definitions. Reading them through is the fastest way to find the ones you cannot define — then drill those in cram mode until you can produce them without the prompt.

Long-term causes of the First World War

Militarism, entangling alliances, imperial rivalry and nationalism — with the Balkan crisis the immediate trigger. The alliance system turned a regional dispute into a general war.

Schlieffen Plan

Germany's plan to defeat France quickly through Belgium before turning on Russia. Its failure produced the trench stalemate and its violation of Belgian neutrality brought Britain in.

Trench warfare

Machine guns and artillery gave defense a decisive advantage, producing static lines and enormous casualties for tiny gains. Verdun and the Somme are the standard evidence.

Total war

The mobilization of an entire society — conscription, war economies, rationing, propaganda and women in industry. It expanded state power permanently and made civilians targets.

Women and the First World War

Large-scale entry into industrial and clerical work, followed by suffrage in several states immediately after. Most were displaced from those jobs when the men returned, which complicates the story of permanent gain.

Russian Revolution, February/March 1917

Bread riots and army mutiny in Petrograd forced the Tsar's abdication. The Provisional Government's fatal decision was to continue the war.

Russian Revolution, October/November 1917

The Bolsheviks seized power under the slogan "Peace, Land, Bread". Lenin then made a punitive separate peace with Germany at Brest-Litovsk.

Treaty of Versailles

1919. Germany lost territory and colonies, was disarmed, accepted the war-guilt clause and owed reparations. Severe enough to enrage and not severe enough to disable — the standard verdict.

War guilt clause

Article 231, assigning Germany responsibility for the war and the legal basis for reparations. Its resentment was central to the appeal of the far right in Weimar Germany.

League of Nations

A collective-security body created at Paris. Fatally weakened by American absence, the absence of enforcement power, and the requirement of unanimity.

Weimar Republic

Germany's democracy from 1919. Burdened by association with defeat, the 1923 hyperinflation, and a constitution whose Article 48 emergency powers were used to bypass parliament.

Great Depression

From 1929. Collapsing trade, mass unemployment and banking failure discredited liberal economics and democratic government, and it is the single most important context for the rise of fascism.

Fascism

Ultranationalist, anti-communist and anti-liberal, organized around a leader, a mass party, paramilitary violence and the subordination of the individual to the nation.

Mussolini

Took power in Italy in 1922 after the March on Rome and built the first fascist state. His corporate state model was widely imitated.

Nazism and Hitler

German fascism with racial ideology at its core. Appointed chancellor in January 1933 through legal channels, and used the Reichstag fire and the Enabling Act to dismantle the republic within months.

Totalitarianism

A regime seeking total control of public and private life through ideology, terror, propaganda and a monopoly party. Applied to Nazi Germany and Stalin's USSR, and the comparison is a standard essay.

Stalin's Five-Year Plans

Forced industrialization from 1928 through central planning, at enormous human cost. Heavy industry grew rapidly and consumer goods and agriculture did not.

Collectivization and the famine

Peasant holdings were forced into collective farms. Resistance was crushed and the resulting famine of 1932–33 killed millions, most severely in Ukraine.

Great Purge

Stalin's terror of 1936–38 against party, army and society, killing or imprisoning millions. It removed most of the Soviet officer corps on the eve of war.

Appeasement

The policy of conceding to Hitler's demands to avoid war, culminating at Munich in 1938. Defended at the time by memory of 1914–18 and by military unreadiness; it convinced Hitler the democracies would not fight.

Nazi-Soviet Pact

August 1939. A non-aggression agreement with a secret protocol partitioning eastern Europe. It freed Hitler from a two-front war and enabled the invasion of Poland a week later.

Second World War in Europe

1939–45. Rapid German victories to 1941, then the reversal at Stalingrad, the Allied landings, and unconditional surrender in May 1945.

The Holocaust

The systematic murder of roughly six million Jews, alongside Roma, disabled people, Poles, Soviet prisoners and others. It proceeded from legal exclusion through ghettoization to industrialized killing, and required bureaucratic participation at every level.

Resistance and collaboration

Occupied Europe produced both, often in the same country. The proportions and motives varied enormously, and an essay treating any nation as uniformly one or the other misstates the evidence.

Consequences of the Second World War

Roughly 60 million dead, Europe divided between two superpowers, colonial empires fatally weakened, and a determination to build international institutions to prevent recurrence.

Alliance system before 1914

The Triple Alliance of Germany, Austria-Hungary and Italy against the Triple Entente of France, Russia and Britain, assembled between 1894 and 1907. It had deterred war repeatedly before 1914, so the useful claim is not that alliances caused the war but that they removed the option of a local one.

Moroccan crises (1905, 1911)

Two German attempts to break the Anglo-French entente by challenging French claims in Morocco, both of which drove Britain and France closer together. They show the alliance system functioning as deterrent and hardening, which is essential context for why 1914 was different.

July Crisis (1914)

The five weeks between the assassination of Franz Ferdinand on 28 June and general war: Germany's assurance to Austria, an ultimatum designed for rejection, Russian mobilization, German declarations of war and the invasion of Belgium. Historians still divide over where responsibility principally lies.

Blank check

Germany's unconditional promise of support to Austria-Hungary against Serbia in July 1914, given before Austria had decided its terms. It is central to arguments assigning Germany primary responsibility, since it removed the restraint Vienna's dependence on Berlin might otherwise have supplied.

New Economic Policy (1921)

Lenin's retreat from War Communism, permitting small private trade and peasant sale of surplus after famine and revolt. It restored production and was reversed by Stalin's Five-Year Plans, so it functions as the road not taken in Soviet economic history.

Spanish Civil War (1936–39)

Franco's Nationalists, backed by Germany and Italy, defeated the Republic, which received aid mainly from the Soviet Union while Britain and France maintained non-intervention. It served as a rehearsal for the coming war — Guernica among the first deliberate bombings of a civilian town — and as evidence of appeasement's logic in practice.

Munich Agreement (1938)

Britain and France conceded the Sudetenland to Hitler without Czechoslovak participation, in exchange for a promise of no further territorial demands. It is the defining case of appeasement, and the standard exam task is to explain the reasoning behind it — memory of 1914–18, rearmament not yet complete — rather than merely to condemn it.

Blitzkrieg

Concentrated armor and air power punching through a narrow front and encircling defenders, rather than the continuous line of 1914–18. Its success in Poland and France in 1939–40 explains why the war's opening was so different from the previous one, and why total defeat came so quickly to France.

Operation Barbarossa (1941)

The German invasion of the Soviet Union, opening the largest and deadliest theater of the war and turning it into a war of annihilation. It also broke the Nazi-Soviet Pact, brought the USSR into the Allied coalition, and committed Germany to the two-front war its strategy had always sought to avoid.

Nuremberg trials (1945–46)

Allied prosecution of Nazi leaders for crimes against peace, war crimes and crimes against humanity — the last category newly defined. They established that following orders is not a defense and laid the foundation of modern international criminal law, while facing the charge of victors' justice.

What examiners penalize here

• Frame Versailles as a **cause of the next war**: its harsh terms, the war-guilt clause, reparations, and lost territory left Germany humiliated and unstable — grievances Hitler exploited. Use this link when a prompt asks about the causes of World War II.
• For comparison prompts, use the **totalitarian model** (one party, leader cult, secret police, propaganda, terror, economic control) to show what Stalin’s USSR and Hitler’s Germany shared, then contrast their **ideologies** (class vs. race). Naming both similarity and difference earns complexity.
• World War II is a hinge point: it left Europe devastated and displaced global power to the **United States and the Soviet Union**, whose rivalry becomes the **Cold War** of Unit 9. Connect the war’s outcome to the bipolar world that followed.
• On women and the vote, avoid the flat claim that the war won it. The strong answer names the wartime contribution *and* the decades of prior campaigning, then uses **France** as the control case: comparable war work, no vote until 1944. Naming a counterexample is what turns an assertion into an argument.

Practice Euro History

Our practice bank is drawn from across the whole course rather than filtered to one unit, which is closer to how the exam asks anyway — it will not tell you which unit a question is testing.

Questions about this unit

All 9 units of AP European History

1. Unit 1 · Renaissance & Exploration
2. Unit 2 · Age of Reformation
3. Unit 3 · Absolutism & Constitutionalism
4. Unit 4 · Scientific, Philosophical, and Political Developments
5. Unit 5 · Conflict, Crisis, and Reaction in the Late 18th Century
6. Unit 6 · Industrialization & Its Effects
7. Unit 7 · 19th-Century Perspectives and Political Developments
8. Unit 8 · 20th-Century Global Conflicts
9. Unit 9 · Cold War & Contemporary Europe