| Term | Definition |
| Cold War | a state of hostility that does not involve combat |
| Hot War | a state of hostility that involves combat and armed warfare |
| containment | to prevent communism from spreading to any new countries |
| ideology | a system of beliefs for economy, politics, or religion |
| hostility | dislike, unfriendliness |
| fallout | radioactivity that comes down to earth after a nuclear explosion |
| civil defense | to defend and protect civilian lives during warfare |
| Berlin Wall | wall that separated East and West Berlin from 1961-1989 |
| iron curtain | name given by Churchill to the border between communist and non-communist states |
| bamboo curtain | name given to the border between communist China and non communist states |
| Truman Doctrine | pledge to help countries defend themselves from communist takeover |
| West Germany | capitalist and democratic German state 1949-1992 |
| East Germany | communist and non-democratic German state 1949-1992 |
| NATO | defensive alliance of western countries (1949) |
| Warsaw Pact | defensive alliance of communist countries (1955) |
| decolonization | act of giving independence to colonies |
| national liberation | when a colony breaks free from a colonial mother country |
| cease-fire | agreement to temporarily stop warfare (not a permanent peace) |
| 38th Parallel | dividing latitude between North and South Korea in 1945 |
| 17th Parallel | dividing latitude between North and South Vietnam in 1953 |
| Marshall Plan | US program to donate money and material to help rebuild European economies |
| Security Council | 15 Member assembly of the United Nations |
| General Assembly | Assembly of every UN member |
| collective security | countries join together for defensive purposes |
| Veto | to cancel an action |
| limited war | to accept less than total victory in a war |
| ballistic missile | a rocket that launches up under its own power but falls to earth by gravity when the engine turns off |
| ground zero | exact center of a nuclear explosion |
| thermonuclear | a hydrogen nuclear weapon |
| Mutual Assured Destruction | idea that both sides would face certain destruction in a nuclear war |