8.2 World War I

Causes of the Great War

Long-term tensions—militarism, alliances, imperialism, and nationalism (MAIN)—set the stage. Europe split into two rival blocs: the Triple Alliance (Germany, Austria-Hungary, Italy) and Triple Entente (France, Russia, Britain). The assassination of Archduke Franz Ferdinand by a Serbian nationalist in June 1914 triggered a chain of alliance obligations and ultimatums, plunging Europe into total war by August 1914.

Total war and stalemate

The Schlieffen Plan failed to deliver quick German victory, producing years of grinding trench warfare on the Western Front. Governments mobilized entire economies and societies—total war—rationing goods, censoring press, and employing propaganda. New technologies (machine guns, poison gas, tanks, airplanes) caused unprecedented casualties, while colonies supplied troops and resources to imperial powers.

Collapse and settlement

Russia exited after the 1917 Revolution (Treaty of Brest-Litovsk), while U.S. entry in 1917 tipped the balance toward the Allies. Germany's economy and morale collapsed by November 1918. The Treaty of Versailles (1919) imposed harsh reparations and territorial losses on Germany and created the League of Nations, but left lasting resentment that contributed to future instability.

Key terms

MAIN causes of WWI

Militarism, Alliances, Imperialism, Nationalism — long-term tensions leading to war.

Schlieffen Plan

Germany's failed strategy for a quick two-front victory, leading to prolonged trench warfare.

Total war

Full mobilization of a nation's economy, society, and resources for the war effort.

Treaty of Brest-Litovsk

1918 treaty in which Russia exited WWI after the Bolshevik Revolution.

Treaty of Versailles

1919 peace settlement imposing harsh reparations on Germany and creating the League of Nations.

Try an AP-style question

The Western Front in WWI became a stalemate because of…

1. fast cavalry charges on both sides
2. a shortage of soldiers on the front
3. early peace negotiations
4. trench warfare and defensive weapons