The Cold War was a conflict between two opposing ideologies: capitalism and communism. Capitalism is an economic system based on private ownership of property and free markets, while communism is an economic system based on public ownership of property and central planning. Democracy is a political system in which the people have the power to choose their leaders, while autocracy is a political system in which one person or a small group of people have all the power. Individualism is a philosophy that emphasizes the importance of the individual, while collectivism is a philosophy that emphasizes the importance of the group.

The Berlin Blockade was a Soviet attempt to starve West Berlin into submission in 1948. The blockade lasted for 11 months and was eventually lifted after the United States and its allies launched a massive airlift to supply the city. The Berlin Blockade is often considered to be the beginning of the Cold War because it was the first major confrontation between the United States and the Soviet Union.

The fall of the Berlin Wall in 1989 is often considered to be the end of the Cold War. The Berlin Wall was a physical barrier that divided East and West Berlin, and its fall symbolized the end of the division of Europe. The dissolution of the Soviet Union in 1991 was another major event that marked the end of the Cold War.

The Truman Doctrine was a policy of containment that the United States adopted during the Cold War. The Truman Doctrine stated that the United States would provide military and economic aid to countries that were threatened by communism. The Truman Doctrine was first applied to Greece and Turkey in 1947, and it was later extended to other countries around the world.

The Brezhnev Doctrine was a policy of peaceful coexistence that the Soviet Union adopted during the Cold War. The Brezhnev Doctrine stated that the Soviet Union would not interfere in the internal affairs of other countries, as long as those countries did not threaten the security of the Soviet Union. The Brezhnev Doctrine was first applied to Czechoslovakia in 1968, and it was later extended to other countries in Eastern Europe.

The arms race between the United States and the Soviet Union during the Cold War was a competition to build more and more powerful weapons. The arms race included the Space Race, the Nuclear Arms Race, and the Conventional Arms Race. The Space Race was a competition to be the first to send a man into space and to the moon. The Nuclear Arms Race was a competition to build more and more powerful nuclear weapons. The Conventional Arms Race was a competition to build more and more powerful conventional weapons, such as tanks, planes, and ships.

The Cuban Missile Crisis was a crisis that occurred in 1962 when the Soviet Union placed nuclear missiles in Cuba. The crisis was resolved when the Soviet Union agreed to remove the missiles from Cuba in exchange for a promise from the United States not to invade Cuba.

The Nixon Doctrine was a policy of détente that the United States and the Soviet Union adopted in the 1970s. The Nixon Doctrine stated that the United States would no longer provide military aid to countries that were threatened by communism, but that the United States would provide economic aid to those countries. The Nixon Doctrine was first applied to Vietnam in 1969, and it was later extended to other countries around the world.

The Perestroika Policy was a policy of economic restructuring that Mikhail Gorbachev introduced in the Soviet Union in the 1980s. The Perestroika Policy was designed to make the Soviet economy more efficient and productive. The Perestroika Policy was unsuccessful, and it contributed to the collapse of the Soviet Union in 1991.

The Glasnost Policy was a policy of openness and transparency that Mikhail Gorbachev introduced in the Soviet Union in the 1980s. The Glasnost Policy was designed to allow for more freedom of expression and to reduce the amount of censorship in the Soviet Union. The Glasnost Policy was successful, and it contributed to the collapse of the Soviet Union in 1991.

The Intermediate-Range Nuclear Forces Treaty (INF) was a treaty that was signed between the United States and the Soviet Union in 1987 to reduce the number of nuclear weapons. The INF Treaty banned all intermediate-range nuclear missiles, which are missiles that have a range of between 500 and 5,500 kilometers. The INF Treaty was successful, and it helped to reduce the risk of nuclear war.

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 START I Treaty banned all strategic nuclear missiles, which are missiles that have a range of over 5,500 kilometers. The START I Treaty was successful, and it helped to reduce the risk of nuclear war.

The Strategic Arms Reduction Treaty (START II) was a treaty that was signed between the United States and the Soviet Union in 1993 to reduce the number of tactical nuclear weapons. The START II Treaty banned all tactical nuclear missiles, which are missiles that have a range of less than 500 kilometers. The START II Treaty was successful, and it helped to reduce the risk of nuclear war.

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) was a treaty that was signed between the United States and the Soviet Union in 1996 to ban all nuclear weapons tests. The CTBT has been signed by over 180 countries, but it has not yet entered into force because it has not been ratified by all of the countries that are required to do so.

The United Nations is an international organization that was created in 1945 to promote international cooperation and security. The United Nations has 193 member states, and it is headquartered in New York City.