- To defeat the Central Powers (Germany, Austria-Hungary, and the Ottoman Empire).
- To enforce the Treaty of Versailles (which ended World War I).
- To prevent Germany from starting another war.
- To spread democracy and make the world a safer place.
While these were the general goals of the Allies, each country had its own specific reasons for fighting.
France
- To regain the territory that Germany had taken from France in the Franco-Prussian War (1870-1871).
- To ensure that Germany could not invade France again.
Great Britain
- To maintain the balance of power in Europe by preventing Germany from becoming too powerful.
- To protect British trade routes.
- To defend Belgium, which Germany had invaded.
Russia
- To expand Russian territory and gain control of the Balkans and the Black Sea.
- To protect Serbia, which had been attacked by Austria-Hungary.
United States
- To end the war and restore peace in Europe.
- To make the world safe for democracy.
- To prevent the spread of communism.