The Truman Doctrine was a policy of containment implemented by the United States during the Cold War. It aimed to prevent the spread of communism by providing economic and military aid to countries threatened by Soviet expansion.

The North Atlantic Treaty Organization (NATO) was a military alliance formed by the United States and its allies in response to the Soviet Union's expansionism. It was established in 1949 and is headquartered in Brussels, Belgium.

The Warsaw Pact was a military alliance formed by the Soviet Union and its allies in response to the establishment of NATO. It was established in 1955 and was dissolved in 1991.

The Cuban Missile Crisis was a crisis that occurred in 1962 when the Soviet Union placed nuclear missiles in Cuba, just 90 miles from the coast of the United States. The crisis was resolved when the Soviet Union agreed to remove the missiles in exchange for a US pledge not to invade Cuba.

Perestroika, Glasnost, and Democratization were all policies implemented by Soviet leader Mikhail Gorbachev in the late 1980s. Perestroika was a policy of economic reform, Glasnost was a policy of political reform, and Democratization was a policy of political liberalization.

The fall of the Berlin Wall on November 9, 1989, marked the official end of the Cold War. The Berlin Wall was a physical and ideological barrier that divided Berlin and Germany into East and West for over 28 years.

Mikhail Gorbachev was the Soviet leader who implemented the policies of Perestroika and Glasnost. He was the General Secretary of the Communist Party of the Soviet Union from 1985 to 1991.

The dissolution of the Soviet Union on December 26, 1991, marked the official end of the Soviet Union. The Soviet Union was a superpower that existed from 1922 to 1991.

The Strategic Arms Reduction Treaty (START I) was a treaty that was signed between the United States and the Soviet Union in 1991 to reduce the number of strategic nuclear weapons. The treaty was signed by US President George H.W. Bush and Soviet President Mikhail Gorbachev.

Reform and Opening Up was a policy of economic and political reform implemented by Chinese leader Deng Xiaoping in the late 1970s. The policy aimed to transform China from a centrally planned economy to a market economy and to open up the country to foreign investment.

The Tiananmen Square protests were a series of student-led demonstrations in Beijing, China, in 1989. The protests were triggered by the death of Hu Yaobang, a former General Secretary of the Communist Party of China, and called for democratic reforms and an end to corruption.

Solidarity was a policy of economic and political reform implemented by Polish leader Lech Wałęsa in the late 1980s. Solidarity was a trade union that was founded in 1980 and played a key role in the collapse of communism in Poland.

The Velvet Revolution was a series of nonviolent protests in Czechoslovakia in 1989 that led to the overthrow of the communist government. The protests were led by students and intellectuals and were supported by the general population.

The New Economic Mechanism was a policy of economic and political reform implemented by Hungarian leader János Kádár in the late 1960s. The policy aimed to decentralize the economy and to introduce market mechanisms.

The Romanian Revolution was a series of violent protests in Romania in 1989 that led to the overthrow of the communist government. The protests were led by the Romanian people and were supported by the military.