Long-term causes: M-A-I-N
- Militarism: great powers built big armies and navies and made war plans. Britain and Germany raced to build battleships.
- Alliances: Europe split into two blocs. The Triple Alliance (Germany, Austria-Hungary, Italy) and the Triple Entente (France, Russia, Britain). A quarrel between two countries could pull in all.
- Imperialism: powers competed for colonies, markets and raw materials in Africa and Asia. Clashes over colonies (for example in Morocco, 1905 and 1911) raised distrust.
- Nationalism: strong pride in one's nation. Some groups, such as Slavs in the Balkans, wanted their own states; this threatened the many-nation Austro-Hungarian Empire. The Balkans were called the "powder keg of Europe".
The spark and the outbreak (1914)
On 28 June 1914 Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, was shot in Sarajevo by a young Bosnian Serb nationalist. Austria-Hungary blamed Serbia and declared war on 28 July. Then the chain reaction:
- Russia mobilised to support Serbia.
- Germany, allied to Austria-Hungary, declared war on Russia and on Russia's ally France.
- Germany invaded neutral Belgium to reach France quickly (the Schlieffen Plan).
- Britain, which had promised to protect Belgium, declared war on Germany (4 August).
Italy stayed out at first and joined the Allies in 1915. The Ottoman Empire (1914) and Bulgaria (1915) joined the Central Powers.
Stages of the war
- 1914: war of movement. The German advance was stopped at the Battle of the Marne. Both sides dug in.
- 1915–1917: war of position (stalemate). On the Western Front a line of trenches ran from the North Sea to Switzerland. Huge battles, such as Verdun and the Somme (1916), killed hundreds of thousands and moved the line only a few kilometres. On the Eastern Front fighting moved more but was also costly. The Allies' Gallipoli landing (1915) failed.
- 1917: the turning year. Germany's unrestricted submarine warfare brought the USA into the war (April). Revolution in Russia led it to leave the war (Treaty of Brest-Litovsk, March 1918).
- 1918: the end. Germany's last big attack in spring failed; the Allies pushed back with fresh US troops and tanks. Germany's allies collapsed, the German emperor gave up the throne and an armistice ended fighting on 11 November 1918.
A global and total war: soldiers and civilians
Total war means a whole society is organised for war, not only the army.
- Soldiers: life in the trenches meant mud, rats, cold, disease and constant danger. New weapons (machine guns, heavy artillery, poison gas, tanks, aircraft, submarines) made attacks very deadly.
- Home front: factories switched to making weapons; governments controlled industry and food (rationing); women took many jobs in factories, transport and nursing.
- Propaganda: posters, films and newspapers encouraged people to join the army and hate the enemy; news was censored.
- Civilians suffered from shortages, blockades, air raids, occupation and forced movement. In the Ottoman Empire, Armenians were deported and massacred in huge numbers from 1915.
- A world war: fighting spread to West Asia, Africa and the oceans. Colonies sent soldiers, workers and money. About 1.3 million Indians served, in France, Mesopotamia (Iraq), Egypt and East Africa; India also paid heavy war costs and faced high prices.
About 9–10 million soldiers and millions of civilians died. The 1918–1919 flu pandemic, spread partly by troop movements, killed even more.
Leaving the war: the peace settlement and a new order
The winners met at the Paris Peace Conference (1919). Separate treaties were made with each defeated power. The Treaty of Versailles (28 June 1919) with Germany:
- the war-guilt clause: Germany accepted blame for the war,
- large reparations (payments for damage),
- a small army (100,000 men), no air force, few ships; the Rhineland demilitarised,
- loss of land in Europe and all colonies.
Consequences
- Four empires ended: German, Austro-Hungarian, Russian and Ottoman. New states appeared in Central and Eastern Europe, for example Poland, Czechoslovakia and Yugoslavia, and others grew, such as Romania.
- The League of Nations (1920) was set up to keep peace, based on US President Wilson's Fourteen Points, but the USA never joined.
- Former Ottoman and German lands in West Asia and Africa became mandates ruled by Britain and France.
- Economic damage, debts and the anger of defeated nations, especially in Germany, helped extremist movements grow and led towards World War II (1939).
- In colonies such as India, broken promises of self-rule and war hardships strengthened national movements.
Try it: build a cause-and-effect chain
Stand 6 dominoes (or books) in a line and label them: Militarism, Alliances, Imperialism, Nationalism, Sarajevo, War. Push the "Sarajevo" one. Why did the others fall only because they were standing close and linked? Now in the 3D free-play step, predict what happened in each year before you move the slider.
Key formulas and definitions
- Causes = MAIN: Militarism, Alliances, Imperialism, Nationalism + spark (Sarajevo, 28 June 1914)
- Allies: France, Britain, Russia (till 1917), Italy (1915), USA (1917), Japan and others
- Central Powers: Germany, Austria-Hungary, Ottoman Empire, Bulgaria
- Key dates: 1914 start and Marne; 1916 Verdun and Somme; 1917 USA in, Russia out; 11 Nov 1918 armistice; 1919 Treaty of Versailles
- Total war: soldiers + home front (industry, women, rationing, propaganda) + colonies
- Results: four empires ended, new states, League of Nations, reparations, mandates
Worked examples
1. Explain how the alliance system turned a local conflict into a world war.
Austria-Hungary attacked Serbia. Russia backed Serbia, so Germany (Austria-Hungary's ally) declared war on Russia and its ally France. Germany's march through Belgium brought in Britain. Each promise pulled in another power, so a Balkan quarrel became a European, then global, war.
2. Why did the Western Front become a stalemate?
Defence was stronger than attack. Deep trenches, barbed wire and machine guns cut down soldiers crossing no man's land, and both sides could rush in reserves by rail. So huge attacks gained very little ground.
3. Give two reasons why 1917 is called a turning point.
1) The USA entered on the Allied side, bringing fresh troops and money. 2) Revolution in Russia took Russia out of the war, letting Germany move troops west for one last attack in 1918.
4. Why did many Germans feel the Treaty of Versailles was unfair?
Germany was not invited to negotiate, had to accept the war-guilt clause, pay heavy reparations, lose land and colonies and shrink its army. Many called it a "dictated peace", and this anger was later used by extremist parties.
Common mistakes
- Saying the assassination alone caused the war. It was the spark; the MAIN causes built up the tension.
- Mixing up the sides: Italy was in the Triple Alliance before the war but fought for the Allies from 1915.
- Thinking the USA fought from the start. It joined only in April 1917.
- Confusing the armistice (11 November 1918, fighting stops) with the Treaty of Versailles (June 1919, peace terms).