The Cold War was the tense fighting between the United States and its allies and the Soviet Union (also called the USSR) and its allies between the end of World War II and the fall of the Soviet Union. It is called the "Cold" War because the Americans and the Soviet Union never actually fought each other directly. Instead, they attacked each other in conflicts known as proxy wars where a powerful country starts a war that they don't fight in.

Conflicting countries 
Most of the countries on one side were allied by NATO, whose most powerful country was the United States. Most of the countries on the other side were allied by the Warsaw Pact, whose most powerful country was the Soviet Union.

The Western Bloc was the name of the capitalist countries led by the United States. The North Atlantic Treaty Organization (NATO) is an alliance created in 1949 and included the United States, the United Kingdom, France, West Germany, Canada, Netherlands, Belgium, Luxembourg, Spain, Portugal, Italy, Norway, Denmark, Greece, and Turkey. Other countries allied with the Western Bloc include Israel, Brazil, South Korea, Kenya (1960-1991), Bangladesh (1964-1968), Pakistan, North Yemen, Malaysia, Saudi Arabia, Philippines, South Africa, Australia and New Zealand.

The Eastern Bloc was the group of socialist countries led by the Soviet Union. The Warsaw Pact was an alliance created in 1955 and included the USSR, Albania, Bulgaria, Czechoslovakia, East Germany, Hungary (until 1976), Poland, and Romania. Other countries allied with the Eastern Bloc included Angola (1975–1991), Cuba, Bolivia, Cambodia (1977–1979), South Yemen, Tunisia, Nepal, Bhutan, Libya (1974–1991), Mongolia (1976–1988), Jamaica, North Korea, China and Laos (1975–1991).

Background 
In February 1917, Tsar Nicholas II of the Russian Empire was overthrown because people were unhappy with their living conditions (like being a serf), especially during World War I. The new government in Russia was a democratic socialist government. Unfortunately, it was ineffective, and people were still unhappy. In November 1917, a communist group called the Bolsheviks, led by Vladimir Lenin, overthrew the new government and were supported by groups of workers called Soviets. The Bolsheviks created a new communist government called the Russian Soviet Federation Socialist Republic (also called simply Soviet Russia or the Russian SFSR).

However, not everyone supported the communists. Many countries that had been part of the Russian Empire had left, such as Latvia, Lithuania, Estonia, and Belarus. The Russian Civil War began, with the Soviet Russian Red Army fighting against the White Army of anticommunist Russians. The White Army was not very united or organized. The Allied Powers of World War I, such as the United States, the United Kingdom, and France, invaded Russia to support the White Army and stop the Red Army. The Red Army eventually won the war in 1922, and established the Union of Soviet Socialist Republics (also called the Soviet Union), along with the newly-formed Socialist Republics of Ukraine, Armenia, Azerbaijan and Georgia.

The start of the Cold War in 1947 was caused by a belief that all governments would become either communist or capitalist. The Western Allies feared that the Soviet Union would spread communism to the rest of Europe and was very concerned that Soviet agents had learnt how to make atomic bombs after the war.

Both nations had opposed Nazi Germany although the United States worked with Nazi scientists and Soviet Union had chosen not to fight with Germany in the Molotov-Ribbentrop pact and the two occupied Poland in 1939. However, Germany turned against the Soviet Union in June 1941 and invaded it during Operation Barbarossa.

After World War II 

After World War II, Germany was left in ruins. The victorious Allies that occupied it split it into four parts. in the western half of Germany, one part was given to the United States, one to the United Kingdom, and one to France. The eastern half was occupied by the USSR. The city of Berlin was also split among the four countries even though it was entirely within the eastern half.

The Federal Republic of Germany (Bundesrepublik Deutschland or BRD), or West Germany, was recognized by the Western Allies in June 1949 and was a capitalist democracy. West Berlin was considered a part of the country. The Soviets named their section of Germany the German Democratic Republic (Deutsche Demokratische Republik or DDR), or East Germany, later in 1949; it was a communist dictatorship.

From April 1948 to May 1949, the Soviets blockaded West Berlin to prevent the city from using West Germany's currency. The United States and its allies supplied the city by airplanes until September 1949 in what became known as the Berlin Airlift. Many East Germans wanted to live in West Germany for having greater quality of life and political freedom. In 1961, the East German government built the Berlin Wall, dividing the two halves of the city, and heavily guarded it to prevent more people from escaping to the west. The wall was considered a symbol of the Cold War and the Iron Curtain that divided Europe.

1950s 

Espionage, or "spying," has been around for a long time and was very important during the Cold War. After its successful nuclear espionage in the Manhattan Project, the Soviets created their spy organs, especially the KGB. The CIA led Americans efforts abroad, and the FBI led counterespionage. Catching foreign spies and fighting domestic subversion  were KGB functions.

In 1953, the Soviet leader Joseph Stalin died, and Nikolai Bulganin and Nikita Khrushchev took his place. Khrushchev later took sole control of the Soviet Union. Khrushchev's Secret Speech marked a period of de-Stalinization, and Khrushchev tried to undo many of the things done by Stalin (such as the Gulag prisons and Stalin's cult of personality).

In the United States, there was a "Red Scare", and when the Soviets detonated their own atom bomb, there was a big political fallout and the United States government made everybody scared about communists. Famous people in many fields who had been Communist sympathizers like in the past like Larry Adler lost their positions. Many actors were 'blacklisted' and so were not hired to act in movies, which ruined their careers. US Senator Joseph McCarthy was believed by many when he accused some important Americans of being communists, including some high government officials.

The 1950s were the beginning of the Space Race between the United States and the Soviet Union. It began with the Soviets putting the Sputnik 1 satellite into orbit around the Earth as the first country in space. The United States responded by starting NASA and soon sent up its own satellites. The Soviets also sent the first man (Yuri Gagarin) into Earth orbit and claimed that proved communism to be the better ideology.

In the 1950s, the United States (under President Dwight Eisenhower) created a policy called "New Look" to cut defense spending and to increase the number of nuclear weapons as a deterrent in order to prevent the Soviet Union from attacking the West. The Soviets also increased their nuclear force, which resulted in mutual assured destruction.

In the Suez Crisis of 1956, the Cold War alliances were broken in an important way for the first time with the Soviet Union and United States favoring one side and Britain and France the other. The Western Allies also decided to let Soviet troops suppress the Hungarian Revolution of 1956.

US Vice-President Richard Nixon engaged in several talks with Khrushchev during the 1950s. One of these was the 1959 "Kitchen Debate" in a model kitchen in Moscow. The debates highlighted the political and economic differences between the Americans and the Soviets. The following year, the United States U-2 spy plane crashed in the Soviet Union. Tensions between the two countries increased.

Cuban Missile Crisis (1962) 

After the United States had invaded Cuba and failed in the Bay of Pigs, the Soviet Union attempted to supply Cuba with nuclear missiles. The missiles in Cuba would have allowed the Soviet Union to target almost the entire United States effectively. In response the United States sent a large number of ships to blockade Cuba to prevent the Soviet Union from sharing the weapons. The United States and Soviet Union agreed that the Soviet Union would no longer give nuclear weapons to Cuba if the United States didn't invade Cuba again. That was the highest period of tension during the Cold War and was the closest the world came to a nuclear war, with possible global conflict to follow.

Détente (1962–1981) 
After the agreement that ended the Cuban Missile Crisis, relations between both sides eased up. Several treaties, designed to reduce the number of nuclear weapons, were signed. In 1964, the US under President Lyndon Johnson invaded North Vietnam, which resulted in a humiliating defeat for the Americans and South Vietnam in 1975. During this period of détente, the United States began building a good relationship with the People's Republic of China, which had once been an ally of the Soviet Union.

End 

The policy of détente ended in 1981, when US Pesident Ronald Reagan ordered a massive military buildup to challenge Soviet influence around the world. The United States began to support anticommunists all over the world with money and weapons. The idea was to help them overthrow their communist governments.

The Soviets had a slow economy during this decade because military spending was at an all-time high. They tried to keep up with the United States in military spending but could not do so. In the Soviet war in Afghanistan, which started in 1979, the Soviets had a difficult time fighting resistance groups, with some of them armed and trained by the United States. The Soviets' failed invasion of Afghanistan is often compared to the American failure during the Vietnam War.

In the late 1980s, the new Soviet leader, Mikhail Gorbachev, made an effort to make an ally of the United States to fix world problems caused by the war, with the ultimate aim of eliminating nuclear weapons. However, that did not take place because Reagan insisted on having a nuclear missile defense system. The people of the Soviet Union were divided. Some wanted Gorbachev to fight harder to eliminate nuclear weapons, but others did not want him to be talking to the United States at all. The mixed feelings created an atmosphere of political infighting, and the people were no longer united behind one goal. Also, the Communist Party started to crumble.

After the fall of the Berlin Wall in 1989 and without communist rule holding together the countries that comprised the Soviet Union, it was divided into smaller countries in 1991 like Russia, Ukraine, Lithuania and Georgia. Eastern Europe got very poor and broken and returned to capitalism. The Cold War was over.

Not all historians agree on when the Cold War ended. Some think it ended when the Berlin Wall fell, but others think it ended when the Soviet Union collapsed in 1991.

References

Other websites 

 Cold War -Citizendium

Cold War