World War I changed the map of the world. This huge conflict waged over four years (1914-1918) pitted the Allies (chiefly France, Britain, Russia, and later, the U.S.) and the Central Powers (Germany, Austria-Hungary, and the Turkish Ottoman Empire) against each other. The end result of the struggle was very dramatic:
- Russia of the Czars disappeared. In the midst of the war, and in some part because of it, the Russian Revolution succeeded, creating the Communist state known as the Union of Soviet Socialist Republics.