World War I (1914–1918) — The Great War

Causes of World War I

World War I was the result of long-term tensions that had been building in Europe for decades. The main causes were:

Militarism: European powers had been building up massive armies and navies, especially Germany and Britain who competed for naval supremacy.

Alliance System: Europe was divided into two armed camps:

• The Triple Alliance: Germany, Austria-Hungary, Italy
• The Triple Entente: Britain, France, Russia

When war broke out between two countries, the alliance system dragged everyone else in.

Imperialism: Competition for colonies in Africa and Asia created tensions between European powers.

Nationalism: Nationalist movements were destabilizing empires, especially the Austro-Hungarian Empire in the Balkans.

The Spark: The assassination of Austro-Hungarian Archduke Franz Ferdinand in Sarajevo on June 28, 1914 by a Serbian nationalist triggered the war.

The Course and Consequences of WWI

The war lasted four years and killed approximately 20 million people. It ended with the defeat of Germany, Austria-Hungary, and the Ottoman Empire.

The Treaty of Versailles imposed harsh terms on Germany:

• Germany lost territory
• Germany was forced to pay massive war reparations
• Germany's military was severely limited
• Germany was forced to accept full blame for the war (the War Guilt Clause)

These harsh terms created resentment in Germany that would contribute directly to the rise of Adolf Hitler and World War II.

The League of Nations

After WWI, US President Woodrow Wilson proposed creating an international organization to prevent future wars. His Fourteen Points included the idea of the League of Nations — the first major international organization designed to maintain world peace through collective security.

The League of Nations was established in 1920 but had serious weaknesses:

• The United States never joined (the US Senate rejected membership)
• It had no military force of its own
• Decisions required unanimous agreement, making action very difficult
• Major powers like Germany and the Soviet Union were initially excluded

The League ultimately failed to prevent World War II.