| Term | Definition |
| Imperialism | establishing colonies to increase the wealth and power of the "mother" country |
| guerrilla warfare | fighting using hit and run tactics |
| Teller Amendment | an addition to the war resolution making it clear that the US didn't want to annex Cuba |
| Boxer Rebellion | secret Chinese societies encouraged to fight against "foreigners" in China |
| Open Door Policy | McKinley sends a note to Japan & European powers stating that all nations should have a right to trade with China |
| Dollar diplomacy | Using economic pressure to force Latin American countries to do what the US wants |
| Roosevelt Corollary | extension of the Monroe Doctrine - warning Europe to stay out of the Americas |
| ABC Powers | Argentina, Brazil & Chile resolve the crisis between US and Mexico |
| nationalism | sense of loyality and pride in ones nation |
| militarism | building up of armies and navies for the possibility of war |
| arms race | competition to have the most and best weapons |
| Red Flag Act | law in the US where a person must walk in front of an automobile with a red flag by day and a red lantern at night to warn pedestrians that a car was coming |
| mustard gas | a new invention in WWI - a yellow colored gas that was fired at the enemy - it caused blindness, damage to the lungs and death |
| trench warfare | a new type of warfare in WWI - troops would dig ditches across from each other and fight from the ditches - they could be quite elaborate but difficult to live in |
| Bolshevik Revolution | the overthrow of the Czar in Russia by a communist government |
| warbonds | a way to fund war - citizens would buy bonds backed by the government |
| Big Four | countries of France, England, the US and Italy were called this after WWI |
| armistice | the ceasing of hostilities - it is not a surrender both sides agree to stop fighting |