Cold War: A period of geopolitical tension between powers in the Eastern Bloc (the Soviet Union and its satellite states) and powers in the Western Bloc (the United States, its NATO allies and others) after World War II.
NATO (North Atlantic Treaty Organization): An intergovernmental military alliance between North American and European countries established by Washington treaty.
Warsaw Pact: A collective defense treaty among eight communist states of Central and Eastern Europe during the Cold War led by USSR.