| A | B |
|---|
| Alliance | A formal agreement or treaty between two or more nations to cooperate for specific purposes. |
| Allies (Allied Powers) | The U.S. joined France, Great Britain, and Russia(in 1917) during World War 1 to make up the Allies. |
| Archduke Franz Ferdinand | Heir to the throne of Austria-Hungary; his assassination was the spark that began World War 1 in Europe. |
| Central Powers | Germany, Austria-Hungary, Turkey, and Bulgaria made up the Central Powers during World War 1. |
| Isolationism | A national policy describing America's policy of avoiding political or economics involvement with other nations. |
| League of Nations | A world organization formed in 1920 to promote international cooperation and peace; first proposed by President Woodrow Wilson, although the U.S. U.S. never joined. |
| Lusitania | Name of an ocean liner sunk by a German submarine in 1915 that helped lead to U.S. intervention in World War 1. |
| Neutrality | A state of being neutral, on neither side in a quarrel or fight, especially nonparticipation in war. |
| Treaty of Versailles | Treaty signed at Versailles, France on June 28, 1919 that officially ended World War 1. |
| Trench Warfare | Ditches dug by soldiers for protection from enemy attacks. |
