- Allies
- the nations that united to oppose Germany and Austria-Hungary, originally, Russia, France, and Britain
- armistice
- a cease-fire agreement
- Balkan League
- an alliance created in 1912 by Greece, Montenegro, Bulgaria, and Serbia against the Ottoman Empire
- Bolsheviks
- a radical majority faction of Russia’s Social Democratic Party led by Vladimir Lenin
- Central powers
- a World War I coalition that included the Austro-Hungarian, German, and Ottoman Empires
- Easter Rising
- the 1916 rebellion of Irish Nationalists against the British in Dublin
- Espionage Act
- a 1917 act passed in the United States that made anti-war propaganda illegal
- Schlieffen Plan
- a German war plan to sweep through Belgium and northern France before turning to Russia
- Sedition Act
- a 1918 act passed in the United States that forbade forms of speech considered disloyal to the war effort
- Sykes-Picot Agreement
- a secret agreement reached between France and Britain in 1916 to partition areas of the Middle East after the war
- total war
- a war fought using all available resources, with no restrictions on weapons or their targets
- Triple Alliance
- a treaty of alliance between Germany, Austria-Hungary, and Italy
- Triple Entente
- a treaty of alliance between France, Russia, and Britain
- U-boats
- German submarines equipped with torpedoes that sank thousands of pounds of cargo over the course of World War I
- War Industries Board (WIB)
- a U.S. federal agency created in 1917 to control the economic and industrial output of factories in times of war
- Women’s Land Army
- a British program to help women ensure enough foodstuffs were produced on farms while men served in the military
- Zimmermann Telegram
- a 1917 telegram sent by Germany’s foreign minister offering an alliance with Mexico in return for Mexico causing disturbances along its U.S. border