GCSE-readyWhy Germany lost the war, 1917 to 1918
In early 1918 Germany seemed close to winning. Eight months later it asked for an armistice. This lesson explains that dramatic turnaround.
1917: one ally in, one ally out
Revolution in Russia led the Bolsheviks to make peace: the Treaty of Brest-Litovsk (3 March 1918) ended the war in the east and freed German troops for the west.
The Spring Offensive and the Allied fightback
But the attackers outran their supplies and lost many of their best soldiers.
The Allies, now under the overall command of Marshal Foch, struck back. At Amiens on 8 August 1918, which Ludendorff called the 'black day of the German army', tanks, aircraft and artillery worked together. The 'Hundred Days' of Allied advances followed.
Collapse at home and abroad
Germany's allies gave up: Bulgaria in September 1918, the Ottoman Empire in October and Austria-Hungary in November.
Sailors mutinied at Kiel and revolution spread. Kaiser Wilhelm II abdicated on 9 November 1918, and the armistice was signed on 11 November 1918.
Explain why the Spring Offensive of 1918 failed.
- German troops advanced fast but outran their supplies of food and ammunition.
- Germany lost many of its best soldiers, who could not be replaced.
- Meanwhile fresh American troops were arriving and the Allies united under Foch, so they could counter-attack.
Answer: It exhausted Germany's best troops and supplies while the Allies, reinforced by the USA, grew stronger.
1917: unrestricted submarine warfare and the Zimmermann Telegram brought the USA in (6 April 1917); Russia left by Brest-Litovsk (3 March 1918). The Spring Offensive (21 March 1918) gained ground but outran supplies. Allied fightback under Foch: Amiens (8 August 1918) and the Hundred Days. Blockade, allies' surrender, Kiel mutiny, Kaiser's abdication (9 November) and armistice (11 November 1918).
- Armistice
- An agreement to stop fighting, such as the one that ended the First World War on 11 November 1918.
- Unrestricted submarine warfare
- Sinking any ship in the war zone without warning, even neutral ones. Germany's use of it from February 1917 helped bring the USA into the war.
- Abdication
- When a monarch gives up the throne, such as Nicholas II in March 1917 or the Kaiser in November 1918.
- Bolsheviks
- The revolutionary Marxist party led by Lenin, which seized power in October 1917 and was renamed the Communist Party in 1918.
All GCSE and International GCSE History key terms and definitions →
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What did the Zimmermann Telegram propose?
- A peace deal with Britain
- A German alliance with Japan against Russia
- An end to submarine warfare
- A German alliance with Mexico against the USA
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Answer: A German alliance with Mexico against the USA
Britain intercepted and decoded it.
What did Russia lose under the Treaty of Brest-Litovsk?
- Moscow
- Huge areas including Poland, the Baltic lands and Ukraine
- Siberia
- Nothing
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Answer: Huge areas including Poland, the Baltic lands and Ukraine
Russia lost much of its population and industry.
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- Pearson Edexcel International GCSE History (4HI1) specification, topic Paper 2, Investigation A1: Key topic 5
- Office of the Historian: U.S. Entry into World War I, 1917
- IWM: Hundred Days Offensive
Checked by the GCSE-ready editorial team, 16 October 2026. Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.