🔑 BIG IDEA

Between 1900 and 1945, global conflict reshaped the political and economic order by:

• Collapsing land-based empires

• Introducing total war

• Expanding state control of economies

• Empowering extremist ideologies

• Weakening imperial systems

• Producing genocide and mass atrocities

This period marks the violent transition from imperial Europe to a world of ideological conflict.

🏛 COLLAPSE OF LAND-BASED EMPIRES (7.1)

Why They Collapsed

Internal:

• Political repression

• Economic inequality

• Nationalism

• Industrial unrest

External:

• World War I military defeat

• Economic strain

• Foreign pressure

• New States That Emerged

• Soviet Union (Russia)

• Republic of Turkey (Ottoman collapse)

• Republic of China (Qing collapse)

• Mexican constitutional state

War destabilized monarchies and empowered revolutionary movements.

⚔️ WORLD WAR I: CAUSES & CONSEQUENCES (7.2–7.3)

Causes (MAIN)

• Militarism

• Alliances

• Imperialism

• Nationalism

Characteristics of Total War

• Government-controlled economies

• Rationing

• Propaganda

• Colonial troop mobilization

• Women entering workforce

Consequences

• 4 empires collapse

• Treaty of Versailles

• Economic instability

• Political extremism

WWI created unresolved tensions that directly fueled WWII.

📉 INTERWAR ECONOMIC INSTABILITY (7.4)

Causes of the Great Depression

• Overproduction

• Speculative investing

• Bank failures

• Trade collapse

Effects

• Mass unemployment

• Political radicalization

• Decline of democratic stability

Government Responses

• Democratic:

  • New Deal (U.S.)

  • Expanded welfare systems

• Authoritarian:

  • Nazi rearmament

  • Stalin’s Five-Year Plans

  • Fascist state control

The economic crisis strengthened extremist regimes.

🌐 IMPERIALISM & INSTABILITY (7.5)

Continued Imperialism

• League of Nations mandates

• Japanese expansion

• Italian expansion

• German territorial demands

Weak Enforcement

• League lacked military power

• Appeasement encouraged aggression

Interwar diplomacy failed to stop militarism.

🔥 CAUSES OF WORLD WAR II (7.6)

• Treaty of Versailles resentment

• Great Depression instability

• Rise of fascism

• Militarism

• Appeasement

• Expansionism

Immediate trigger:

• Germany invades Poland (1939)

WWII was the result of unresolved WWI tensions and failed diplomacy.

💣 WORLD WAR II AS TOTAL WAR (7.7)

Characteristics

• Strategic bombing

• Firebombing

• Forced labor

• Industrial mobilization

• Civilian targeting

Key Developments

• Holocaust

• Atomic bomb

• Massive civilian casualties

WWII intensified total war to an unprecedented scale.

⚠️ GENOCIDE & MASS ATROCITIES (7.8)

Extremist ideologies justified targeting populations.

Examples:

• Armenian Genocide

• Holodomor

• Holocaust

• Cambodian Genocide

• Rwandan Genocide

State-sponsored violence became systematic and industrialized.

🧠 MAJOR IDEOLOGIES TO KNOW

• Fascism

• Totalitarianism

• Communism

• Militarism

• Nationalism

You should be able to compare how each shaped domestic and foreign policy.

🎯 MUST-KNOW EXAMPLES FOR THE EXAM

• Russian Revolution (1917) 

Why it matters: Shows how war + internal weakness caused regime collapse.

• Treaty of Versailles

Why it matters: Direct cause of German resentment and Nazi rise.

• Great Depression

Why it matters: Global economic crisis that destabilized democracies.

• League of Nations

Why it matters: Weak enforcement enabled aggression.

• Japanese Invasion of Manchuria

Why it matters: Example of interwar imperialism ignored by League.

• Munich Agreement

Why it matters: Peak appeasement failure.

• Anschluss

Why it matters: Expansion justified by nationalism.

• Molotov-Ribbentrop Pact

Why it matters: Enabled invasion of Poland.

• Blitzkrieg

Why it matters: Demonstrates mechanized warfare.

• Stalingrad

Why it matters: Major turning point in WWII.

• Holocaust

Why it matters: Industrial genocide under extremist ideology.

• Atomic Bomb

Why it matters: Ended WWII and began nuclear age.

• Five-Year Plans

Why it matters: Example of state-directed economic control.

• New Deal

Why it matters: Democratic economic intervention.

• Armenian Genocide

Why it matters: Early 20th-century genocide precedent.

• Holodomor

Why it matters: State-engineered famine as political control.

• Rwandan Genocide

Why it matters: Demonstrates ideology + propaganda driving violence.

• Total War

Why it matters: Core concept connecting both world wars.

📚 SKILLS YOU MUST MASTER FOR THE EXAM

You should be able to:

• Explain causation chains (WWI → Depression → WWII)

• Compare democratic vs authoritarian responses

• Analyze how economic crises fueled extremism

• Evaluate how total war changed societies

• Use specific evidence in every response

• Identify continuity and change from 1900–1945