- Too many complex military alliances in Europe
- Rise of European nationalism (extreme patriotism)
- Assassination of Austria-Hungary's Archduke Franz Ferdinand
Central Powers Allied Powers
Germany United Kingdom
Ottoman Empire Russia
United States (1917-1918)
The U.S. considered this to be a European war and didn't want to intervene; Wilson wanted to keep America neutral.
But if President Woodrow Wilson wanted to keep America out of the war, why did the U.S. join?
- Germany sunk the ship Lusitania; 128 Americans died.
- German U-boats (submarines) kept sinking U.S. merchant ships
- Allied spies found out about the Zimmerman telegram, a note from Germany to Mexico saying if the Mexicans joined the Central Powers, Germany would give Texas and the Southwestern U.S. back to Mexico if it won the war.
The U.S. joined the Allies, and within a year and a half, World War I was over.
The Treaty of Versailles ended the war officially, and placed harsh conditions on Germany: it had to give up lots of its land, its natural resources, and had to pay back the Allies. This bankrupted Germany, and helped Adolf Hitler rise to power several years later.