World History · PT13.3.1

World War I (1914–1918)
Causes, Course & Consequences

The "war to end all wars" — how imperial rivalries, alliance systems, and a single assassination plunged the world into four years of industrial slaughter.

MAIN Causes of WWI

Historians use the acronym MAIN to organise the long-term causes of WWI:

LetterCauseKey Examples
MMilitarismGermany's army doubled 1870–1914; Anglo-German naval race (Dreadnoughts); conscription across Europe
AAlliance SystemTriple Alliance (Germany, Austria-Hungary, Italy) vs. Triple Entente (France, Russia, Britain)
IImperialismMorocco Crises (1905, 1911); colonial rivalry in Africa and Asia; competition for raw materials
NNationalismPan-Slavism in Balkans; German nationalism; Austro-Hungarian multi-ethnic tensions; Balkan Wars 1912–13
Memory Aid — MAIN Militarism · Alliances · Imperialism · Nationalism. These were the underlying causes. The assassination of Franz Ferdinand was only the immediate trigger.

Triple Alliance vs. Triple Entente

AllianceMembersBecame (in War)
Triple Alliance (1882)Germany, Austria-Hungary, ItalyCentral Powers (Italy defected 1915; joined Entente)
Triple Entente (1907)France, Russia, BritainAllied Powers
Later additions (Allied)Italy (1915), USA (1917), Japan
Later additions (Central)Ottoman Empire (1914), Bulgaria (1915)
⚠ Examiner Trap #1 Italy was part of the Triple Alliance (with Germany and Austria-Hungary) before WWI but did NOT join Germany in the war. Italy declared neutrality in 1914, then switched to the Allied side in 1915 (Treaty of London). UPSC MCQs often give Italy as a Central Power.

Assassination of Archduke Franz Ferdinand

On 28 June 1914, Archduke Franz Ferdinand — heir to the Austro-Hungarian throne — was assassinated in Sarajevo (Bosnia) by Gavrilo Princip, a member of the Serbian nationalist group Black Hand. Austria-Hungary blamed Serbia and issued an ultimatum; Serbia's partial acceptance was rejected. Austria-Hungary declared war on Serbia (28 July 1914), triggering the alliance system — Russia mobilised to defend Serbia; Germany declared war on Russia; then France; Germany invaded Belgium; Britain declared war on Germany (4 August 1914) under the Treaty of London (1839) which guaranteed Belgian neutrality.

⚠ Examiner Trap #2 Gavrilo Princip was a Bosnian Serb, member of the Black Hand (Ujedinjenje ili smrt) — he was NOT an official Serbian government agent. Austria-Hungary blamed the Serbian state, but the assassination was carried out by a nationalist group, not the government. UPSC options sometimes imply it was a state-sponsored act.

Key Events & Battles 1914–1918

YearEventSignificance
Aug 1914Schlieffen Plan fails at Battle of MarneGermany fails to knock out France quickly; war becomes two-front
1914–18Trench warfare on Western FrontStalemate; 700km of trenches; poison gas (Germany first used April 1915)
Apr–Dec 1915Gallipoli CampaignAllied failure to open Dardanelles; 250,000 Allied casualties; ANZAC legend
Jul–Nov 1916Battle of the Somme60,000 British casualties on Day 1 (1 July); first use of tanks (September 1916)
Feb–Dec 1916Battle of Verdun~700,000 casualties; longest battle of WWI; France-Germany
May 1916Battle of JutlandLargest naval battle; British vs. German fleet; strategic British victory
Apr 1917USA enters warTriggered by unrestricted submarine warfare + Zimmermann Telegram
Nov 1917Balfour DeclarationBritain promises Jewish homeland in Palestine — shapes Middle East conflict
Mar 1918Treaty of Brest-LitovskRussia exits war; Germany shifts forces to Western Front
11 Nov 1918Armistice — Germany surrendersEnd of WWI; 11th hour, 11th day, 11th month 1918

Treaty of Versailles (28 June 1919)

Signed exactly five years after the assassination that started the war, the Treaty of Versailles imposed harsh terms on Germany:

  • War guilt clause (Article 231): Germany accepted sole responsibility for the war.
  • Reparations: £6.6 billion (finalized 1921 London Schedule) — not paid in full until October 2010.
  • Territorial losses: Alsace-Lorraine to France; Rhineland demilitarised; Polish Corridor created; Danzig made a Free City; all colonies lost.
  • Military restrictions: Army capped at 100,000; no Air Force; no submarines.
  • League of Nations: Created (Wilson's 14th Point); USA ironically did NOT join (Senate rejection).
⚠ Examiner Trap #3 The USA proposed the League of Nations (Wilson's Fourteen Points) but did not join it — the US Senate refused to ratify membership (led by Senator Henry Cabot Lodge). The USA therefore was never a member of the League it created. UPSC frequently tests this irony.

Previous Year Questions

UPSC Prelims — Statement-Based

Q. Consider the following about the Treaty of Versailles:
1. It established the League of Nations.
2. The United States was a founding member of the League of Nations.
3. Germany was required to accept full responsibility for the war.
Which is/are correct?

(a) 1 and 3 only   (b) 1 and 2 only   (c) 2 and 3 only   (d) 1, 2 and 3

Answer: (a) — Statement 2 is wrong. The USA proposed the League (Wilson's 14 Points) but the Senate refused to ratify US membership. Statements 1 (Part I of Versailles Treaty = League Covenant) and 3 (Article 231 "war guilt clause") are correct.

UPSC Prelims — Identification

Q. The Zimmermann Telegram (1917) was a secret communication from Germany to:

(a) Austria-Hungary proposing naval strategy   (b) Mexico proposing an alliance against the USA   (c) Russia offering a separate peace   (d) Britain proposing armistice

Answer: (b) — Germany's Foreign Secretary Arthur Zimmermann sent a telegram to Mexico proposing that if the USA entered the war, Mexico should attack the USA in return for German support to recover Texas, New Mexico and Arizona. British intelligence intercepted it; its publication helped turn American public opinion toward entering the war.

FAQ

What was the Schlieffen Plan and why did it fail?
The Schlieffen Plan (developed 1905) was Germany's strategy to fight a two-front war: quickly knock out France by attacking through neutral Belgium, then shift forces to fight Russia (which was expected to mobilise slowly). It failed because (1) Belgium resisted and Britain entered the war; (2) France stopped the German advance at the Battle of the Marne (September 1914); (3) Russia mobilised faster than expected. The failure condemned Germany to the two-front war it had wanted to avoid.
What was the significance of the Gallipoli campaign for India?
Indian troops fought at Gallipoli alongside ANZAC (Australian and New Zealand) forces. The campaign (April–December 1915) aimed to open a sea route to Russia through the Dardanelles and knock the Ottoman Empire out of the war. It failed catastrophically (250,000 Allied casualties). The Indian Corps and the ANZAC experience at Gallipoli became founding narratives of national identity for Australia and New Zealand. For India, the high casualties with no resulting reform deepened nationalist disillusionment.
What is the connection between WWI and the Middle East today?
Three WWI-era decisions shaped the modern Middle East: (1) Sykes-Picot Agreement (1916) — Britain and France secretly divided Ottoman Arab territories between themselves, drawing the modern borders of Iraq, Syria, Lebanon, and Jordan. (2) Balfour Declaration (1917) — Britain promised a Jewish homeland in Palestine, creating the foundation for the Arab-Israeli conflict. (3) Mandate system — League of Nations gave Britain and France control over former Ottoman territories as "mandates."
How did WWI contribute to WWII?
The harsh terms of Versailles — the war guilt clause, massive reparations, and territorial humiliation — created German resentment that Adolf Hitler exploited. The Great Depression (1929) destroyed the economic stability that had made Weimar Germany work. The League of Nations lacked teeth (no USA, no enforcement mechanism) to stop aggression. Virtually every historian treats WWI's settlement as a direct cause of WWII — Churchill called it "the Thirty Years' War" (1914–1945).

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