Match each term with its definition 3 conflict between communist North Vietnam and Viet Cong (communist- led guerrillas) and the anti- Communist South Vietnam and its ally, the United States. Line that divides North and South Korea. A conflict that started between communist North Korea and South Korea which soon involved the USA and the USSR. Began with the installation of nuclear missiles in Cuba by the Soviet Union. known as one of the most intense conflicts of the Cold War. Doctrine stating that the USA would provide political, military and economic assistance to all democratic nations under threat from external or internal Co 1. Korean War 2. 38th Parallel 3. Cuban Missile Crisis 4. Vietnam War 5. Truman Doctrine.