World War I
Explain causes, technologies, home fronts, total war, treaty settlements, and global consequences of World War I.
A lesson of World History, in The Twentieth Century, about 10 minutes.
By the end of this lesson, you will be able to explain the long-term and immediate causes of World War I, describe the major phases of the war, analyze why it was unprecedented in its scale and methods, and explain its consequences.
MAIN: The Long-Term Causes
Historians use the acronym MAIN to identify the four long-term causes:
M — Militarism: European powers had built massive armies and navies in the decades before 1914. The Anglo-German naval arms race was particularly intense. Military planning was rigid — the German Schlieffen Plan required attacking France first through Belgium regardless of circumstances.
A — Alliance systems: Europe was divided into two armed camps:
- Triple Alliance: Germany, Austria-Hungary, Italy
- Triple Entente: France, Russia, Britain These alliances meant a conflict between two states could automatically involve six.
I — Imperialism: competition for colonies created conflicts among powers — especially Germany, which felt it had not gotten its "place in the sun."
N — Nationalism: Pan-Slavic nationalism (supported by Russia) challenged Austria-Hungary's multi-ethnic empire. Ethnic minorities within empires demanded self-determination. Germany promoted aggressive German nationalism.
The Spark: Assassination at Sarajevo
June 28, 1914: Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, was assassinated in Sarajevo (Bosnia) by Gavrilo Princip, a Bosnian Serb with ties to the Black Hand — a Serbian nationalist group.
Austria-Hungary blamed Serbia and issued an ultimatum. When Serbia partially refused, Austria-Hungary declared war (July 28, 1914). The alliance system then pulled in:
- Russia mobilized to support Serbia
- Germany declared war on Russia, then France
- Germany invaded Belgium (per the Schlieffen Plan)
- Britain declared war on Germany (treaty with Belgium + strategic interest)
Within 6 weeks, the great powers of Europe were at war.
The War's Character: Unprecedented Industrialized Slaughter
Trench warfare: the Western Front quickly bogged down into hundreds of miles of trenches. Neither side could advance; years of attacks gained little territory at massive cost.
New weapons:
- Machine guns: made frontal assaults suicidal
- Artillery: killed more soldiers than any other weapon; constant bombardment ("shell shock")
- Poison gas (chlorine, mustard gas): Germany first used it at Ypres (1915)