Since the seventeenth century, Vietnam had been a colony of France. Vietnamese nationalists defeated the French at the Battle of Dien Bien Phu (1954). Buddhist monk set himself on fire in Saigon to protest the government's favoring of Roman Catholics over Buddhist (1963).

Domino theory; belief that if one country in a region falls to communism, other countries would soon follow, like dominos in a line. Policy led to U.S. support of an undemocratic and unpopular South Vietnamese ruler, Ngo Dinh Diem.

North Vietnamese leader Ho Chi Minh oppose the U.S. and wanted to unite Vietnam under a single communist government. Vietcong; South Vietnamese who supported the Communist, fought guerrilla war against US troops.

A U.S. antiwar movement developed. Tet Offensive; North Vietnamese and Vietcong attack, though not a military success, demonstrated that the United States was having difficulty winning the war (1968). Pres. Nixon began to withdraw US troops (1971), and the final troops pulled out in 1975.

After the 1960s, relationships between the superpowers improved. Détente; a period of relaxed relations between nations. One symbol of détente was the visit of Pres. Nixon to the Soviet Union and China (1972). U.S. and U.S.S.R. signed the strategic arms limitation Treaty (SALT), designed to limit the number of Intercontinental ballistic missiles.

Soviets invasion of Afghanistan (1979), worsened relations. U.S. arm Osama bin Laden to fight the Soviets. Afghanistan an arena for a “hot war” between Soviet-backed communist forces and U.S.-backed resistance forces. U.S. armed Osama bin Laden.

Pres. Reagan referred to Soviet Union as the "evil Empire” increasing tension. “Strategic Defense initiative" (SDI), called "Star Wars," the system would supposedly destroy any Soviet nuclear missile that targeted the United States or its allies.

Soviets were unable to keep up with U.S. technology. Lack of funds needed for research.

Mikhail Gorbachev came to power (1985). Began the policies of: Perestroika; economic restructuring and more leeway for private ownship of businesses. Glasnost; opening up Soviet society and the political process by granting greater freedom. Soviet economic reforms to revive it stagnant economy was failure; because the planned economy was dismantled before a functioning market- based system could emerge.

Both nations signed treaty to restrict intermediate- range nuclear weapons in Europe (1987).

Gorbachev’s policies led to democratic reform movements in Eastern European nations (1989). Though East Europe was a communist bloc, bitter and divisive conflict undermined any sense of communist solidarity. Berlin wall came down and Germany reunited as one country (1990).

Democratic reforms also swept the Soviet Union, as Lithuania, Georgia, and other Soviet republics declared independence. A key theme of Russian history since 1985 has been the dissolution of the communist system. The collapse of the Soviet Union and the end of communism has led to open conflict among different ethnic groups living within the same state

Gorbachev's reforms led to the end of the Soviet Union (1991), ending the Cold War. In the twenty-first century, international tensions born of communism remain East Asia and the Caribbean.

That concludes the Cold War.