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Europe During the
Interwar Period

Explore the political upheaval, economic crises, and ideological conflicts that reshaped Europe between 1919 and 1939, setting the stage for the Second World War.

AP European History

What Was the Interwar Period?

The Interwar Period spans from the end of World War I in 1918 to the outbreak of World War II in 1939. These two decades witnessed the collapse of empires, the birth of new nations, dramatic economic swings, and the rise of radical ideologies that would transform the continent.

Key Terms to Know

Totalitarianism
A system where the state exercises absolute control over all aspects of public and private life.
Appeasement
The diplomatic policy of making concessions to aggressive powers to avoid direct conflict.
Collective Security
The idea that nations band together to deter aggression; embodied by the League of Nations.
Hyperinflation
Extremely rapid, out-of-control price increases that devastated economies like Weimar Germany in 1923.
Autarky
Economic self-sufficiency; fascist states pursued it to reduce dependence on foreign trade.

A Timeline of Crisis

1919
Treaty of Versailles
Imposed harsh reparations and territorial losses on Germany
1922
Mussolini's March on Rome
Fascists seized power in Italy, establishing Europe's first fascist state
1923
German Hyperinflation
The mark collapsed; prices doubled every few days
1929
Great Depression Begins
Wall Street crash triggered global economic collapse
1933
Hitler Becomes Chancellor
Nazi Party took power in Germany through legal means
1938
Munich Agreement
Britain and France ceded the Sudetenland to Germany
1939
Invasion of Poland
Germany invaded Poland, beginning World War II

The Treaty of Versailles

Signed in June 1919, the Treaty of Versailles was the settlement that ended World War I. Its punitive terms toward Germany became a central grievance that destabilized the entire interwar order.

1
War Guilt Clause (Article 231): Germany accepted sole responsibility for causing the war.
2
Reparations: Germany owed 132 billion gold marks, crippling its economy for years.
3
Territorial losses: Alsace-Lorraine returned to France; new states carved from German and Austrian land.
4
Military restrictions: Army limited to 100,000 troops; no air force; demilitarized Rhineland.

The Rise of Totalitarianism

Totalitarianism Fascism (Italy) Nazism (Germany) Stalinism (USSR) Mussolini, 1922 Corporate state Nationalist revival Cult of personality Hitler, 1933 Racial ideology Lebensraum Anti-Semitism Stalin, 1924 Command economy Five-Year Plans Great Purges Shared: Secret police / Propaganda / Single-party rule / Censorship

Fascism vs. Communism

Fascism Communism
Economic Model State-directed capitalism State ownership of production
Class View Class collaboration under the nation Class struggle; abolish bourgeoisie
Nationalism Extreme: national superiority Internationalist in theory
Leadership Charismatic dictator (Il Duce, Fuhrer) Party vanguard (General Secretary)
Goal National rebirth and expansion Classless, stateless society
Opposition Communism, liberalism, democracy Capitalism, fascism, bourgeois democracy

The Great Depression Hits Europe

Industrial Output Index 1928 1929 1930 1932 1935 0 50 100 150 Germany Britain France

Why Weimar Failed

The Weimar Republic (1919-1933) was Germany's first democracy, yet it collapsed in just 14 years. Understanding why requires examining multiple interacting factors:

1
Stab-in-the-back myth: Many Germans believed the army was "undefeated" and that politicians had betrayed them by signing the armistice.
2
Proportional representation: Fragmented parliament meant no party could govern alone, leading to weak coalition governments.
3
Article 48: Emergency presidential powers allowed governance by decree, later exploited by Hitler.
4
Economic catastrophe: Hyperinflation (1923) and the Great Depression (1929-33) destroyed public faith in democratic institutions.
5
Political violence: Extremists on both the far left and far right used street violence, assassinations, and coups against the republic.

The League of Nations

Established in 1920 as part of the Treaty of Versailles, the League of Nations was the world's first intergovernmental organization dedicated to maintaining peace. It was Woodrow Wilson's vision, yet the U.S. Senate refused to join.

Successes
Resolved minor disputes (Aaland Islands, 1921); improved labor standards through the ILO; managed refugee crises.
Failures
Could not stop Japan in Manchuria (1931), Italy in Ethiopia (1935), or Germany's rearmament. Had no army of its own.

How to Analyze Interwar Causation

AP European History essays require you to construct causal arguments. Use this framework to connect events in the interwar period:

1
Identify the structural cause: What long-term conditions made the event possible? (e.g., Versailles resentment, weak democratic institutions)
2
Identify the trigger: What short-term event set the crisis in motion? (e.g., Great Depression, Reichstag Fire)
3
Trace the mechanism: How did the cause produce the effect? Who were the key actors and what choices did they make?
4
Evaluate significance: Was this a necessary or sufficient condition? Could the outcome have been different?
5
Connect to broader themes: Link to AP themes: political power, economic change, cultural developments, or international diplomacy.

Case Study: Hitler's Rise to Power

Versailles Resentment Weak Weimar System Anti-Communist Fear Great Depression (1929) Mass unemployment + political paralysis Elites appoint Hitler as Chancellor (Jan 1933) Nazi Dictatorship Enabling Act, March 1933

Case Study: The Spanish Civil War

The Spanish Civil War (1936-1939) was a brutal proxy conflict that previewed the ideological battle lines of World War II.

Nationalists
Led by Francisco Franco. Supported by fascist Italy and Nazi Germany (Condor Legion). Army officers, Catholic Church, monarchists, landowners.
Republicans
Elected government. Supported by the Soviet Union and International Brigades (volunteers). Socialists, communists, anarchists, trade unions.

Appeasement and the Road to War

Rearmament 1935 Rhineland March 1936 Anschluss March 1938 Sudetenland Sept 1938 Poland Invaded Sept 1939 Escalation

Common Mistakes to Avoid

✕ Single-Cause Thinking
Saying "Versailles caused WWII" is too simple. Multiple structural, economic, and political factors interacted. Always cite at least two or three causes.
✕ Treating All Fascisms as Identical
Italian Fascism, German Nazism, and Spanish Falangism had important differences in racial ideology, economic policy, and religious relationships.
✕ Hindsight Bias
Judging appeasement as "obviously foolish" ignores that leaders in the 1930s had just lived through WWI and desperately wanted to avoid another war.

Summary of Key Developments

Theme 1919-1929 1929-1939
Economy Recovery, U.S. loans, brief prosperity Depression, autarky, rearmament
Politics New democracies, fragile coalitions Authoritarian takeovers across Europe
Ideology Liberal internationalism, League of Nations Fascism and communism dominate
Diplomacy Locarno, Kellogg-Briand, collective security Appeasement, broken treaties, aggression
Culture "Roaring Twenties," modernism, jazz age Propaganda states, censorship, exile

Question 1 of 5

Which provision of the Treaty of Versailles required Germany to accept sole responsibility for starting World War I?

Question 2 of 5

Which event is most commonly identified as the immediate trigger for the Nazi Party's rapid growth in electoral support?

Question 3 of 5

On which point do these two historians disagree?

Question 4 of 5

What distinguishes fascism from communism in their approach to class and economics?

Question 5 of 5

The Munich Agreement of 1938 is most often cited as evidence for which historical argument?