AMSCO 7.2 Causes of World War I Notes

Overview

AMSCO Topic 7.2, "Causes of World War I," covers why a regional assassination in the Balkans exploded into the first truly global war (1914-1918). The chapter (AMSCO p. 461-465) splits the causes into one immediate trigger, the assassination of Archduke Franz Ferdinand by Gavrilo Princip in June 1914, and four long-term tensions you can remember with the acronym MAIN: Militarism, Alliances, Imperialism, and Nationalism. This topic sits at the heart of Unit 7 (Global Conflict, 1900-present) and builds directly on the shifting power dynamics from Topic 7.1.

The big idea: the assassination was the spark, but Europe was already soaked in gasoline. Decades of arms races, secret defense pacts, colonial rivalry, and nationalist movements meant a "damned foolish thing in the Balkans" (as German Chancellor Otto von Bismarck predicted back in 1888) could pull every major power into war.

Timeline of the beginning of World War I. Image courtesy of Vibhi.

The Immediate Cause: Assassination of Archduke Franz Ferdinand

The immediate cause of World War I was the assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and his wife Sophie on June 28, 1914. The assassin, Gavrilo Princip, was a Serbian member of the Black Hand, a nationalist organization devoted to ending Austro-Hungarian presence in the Balkans. To Serbian nationalists, the Black Hand fought for liberation. To Austria-Hungary, it was a terrorist group. Serbian nationalists were specifically protesting Austria-Hungary's control over Bosnia-Herzegovina.

The chain reaction, summer 1914

Watch how fast the alliance system turned one assassination into a world war:

• Austria-Hungary sent Serbia an ultimatum demanding an end to all anti-Austrian agitation. Serbia rejected it.
• July 28, 1914: Austria-Hungary declared war on Serbia, counting on its stronger ally Germany for firepower.
• Serbia, populated by ethnic Slavs, looked to fellow Slavic countries, especially Russia, for protection.
• August 1: Germany declared war on Russia.
• August 3: Germany declared war on France.
• August 4: Britain declared war on Germany.
• August 6: Austria declared war on Russia.
• By the end of August 1914, Japan entered the conflict, turning a relatively minor Balkan incident into a true world war.

This sequence is FRQ gold. If you're asked to explain how regional conflict escalated globally, this is your evidence.

Long-Term Causes: MAIN

Princip's bullets were not the sole cause. Tensions had been simmering in Europe for decades, and the AMSCO chapter organizes them with the acronym MAIN.

Militarism

Militarism is aggressive military preparedness, a culture that celebrates war and the armed forces. European powers proved their strength by pouring money into armies and navies. Great Britain and Germany in particular spent heavily, recruiting young men and building ships and other military hardware. The Industrial Revolution made it possible to mass-produce weapons and supplies, which raised the stakes of any conflict.

Militarism also shaped public attitudes. War looked like a festive competition, more game than tragedy. British soldier Bill Haine recalled, "Everybody said, 'It'll be over by Christmas.'" Spoiler: it lasted four years.

Alliances

European nations formed secret alliances, agreements to protect and defend one another when attacked. If one member was attacked, the others were expected to jump in. That's exactly why Russia and Germany piled into a quarrel between Serbia and Austria-Hungary.

The two big rival blocs before the war:

• Triple Entente: Britain, France, and Russia. All three saw Germany as a rival, for different reasons. France was bitter about losing the Franco-Prussian War (1870-1871) and losing Alsace-Lorraine, a major industrial region rich in iron ore, to Germany. Both Britain and France competed with Germany for colonies in Africa.
• Triple Alliance: Germany, Austria-Hungary, and Italy.

Once the war began, the names changed:

• The Triple Entente became the Allies, eventually joined by Italy, Japan, China, the United States, and others. By war's end there were 27 Allies and "Associated Powers."
• The Triple Alliance became the Central Powers when the Ottoman Empire and Bulgaria joined. Italy stayed neutral until 1915, then switched sides and joined the Allies.

Quick reference for who lined up where:

Imperialism

The alliance system grew out of imperial rivalry. Owning overseas colonies was one of the most important ways European nations asserted power and generated wealth. During the late 19th century, Western European countries scrambled for any available land in Africa to add to colonies they already held in Asia, the Americas, and the Pacific. Once nearly all of Africa was claimed, European powers started fighting each other over colonies. Competition for resources and territory kept the rivals on edge long before 1914.

Nationalism

Nationalism starts as pride in one's national identity, but in multinational empires it became explosive. The Ottoman Empire and Austro-Hungarian Empire each ruled many ethnic groups with their own nationalist movements. Serbs like Princip wanted to throw off Austro-Hungarian domination. Arabs were tired of Ottoman restrictions.

Both groups sought self-determination, the idea that people sharing the same ethnicity, language, culture, and political ideals should be united and have the right to form an independent nation-state. Militant Serb and Arab nationalists fought for the Allies, which extended the boundaries of the Great War even further.

Consequences of the Great War

World War I reshaped the entire 20th century. The AMSCO chapter argues that virtually every major event of the rest of the century was a direct or indirect result of the war. Know these outcomes:

• Four monarchies fell: Russia, Austria-Hungary, Germany, and the Ottoman Empire.
• Maps were redrawn in Europe and the Middle East as the Austro-Hungarian and Ottoman empires disintegrated. Germany lost all its overseas colonies to Allied nations, and former Ottoman provinces (Iraq, Palestine, Syria, Lebanon) came under British and French control.
• Colonialism began to crumble. The war weakened Western European powers, fueling nationalism and demands for self-rule in their Asian and African colonies.
• New technologies made it the deadliest, most destructive war in human history up to that point. No previous war had involved as many nations or killed as many soldiers and civilians.
• Economic and social upheaval followed: the rise of communism and fascism, colonial revolts, genocide, and a massive shift of power from Europe to the United States.
• The peace treaty set up World War II. Germany was forced to take full blame for the war (even though Austria-Hungary started it) and to pay reparations, impossibly large payments to its opponents. German fury over these terms helped authoritarian regimes rise. The treaties signed at the war's end helped set the stage for World War II.

The irony the chapter highlights: Europeans entered the 20th century expecting peace guaranteed by alliances, prosperity from colonial empires, and continued progress. The war that was supposed to make the world safe for democracy instead produced authoritarian regimes and an even bigger war.

Key Terms to Know

Practice and Next Steps

Pair these AMSCO notes with the Topic 7.2 Causes of World War I study guide for the College Board's framing of the same material, then continue to AMSCO 7.3 Conducting World War I to see how the war was actually fought. You can find every chapter summary on the AP World AMSCO notes page.

To check your understanding:

• Run through AP World guided practice questions on Unit 7 to test the MAIN causes and the 1914 chain of events.
• Try a causation prompt with FRQ practice and instant scoring. World War I's causes and consequences are a classic LEQ setup.
• Skim the AP World key terms glossary if any vocabulary above still feels shaky.