There was an intense ideological struggle between the U.S. and the USSR that witnessed low-intensity proxy wars, but did not escalate into a direct confrontation between the two biggest superpowers of the time. That is what the Cold War was; the people did not want WWIII, after already two World Wars.
There were many causes for the Cold War. One is that the post-war world was a bipolar world, the entirety of Europe was divided into two. There was the Red Army’s occupation of Eastern Europe and Eastern Germany, while the Western Europe was a world of democracy. The United States’ and USSR had completely incompatible political and economic systems. They are directly opposite on the political compass. The United States was determined to shield Western Europe from communism as well, because communism was the enemy of capitalism.
Churchill’s Iron Speech in 1946 was in Fulton, Missouri on the 5th of March. He spoke about how Eastern and Western Europe is divided and different because of communism, and there is an “Iron Wall.” As the United States was determined to shield Western Europe from communism, in 1947, Truman proposed the idea of “containment,” called the “Truman Doctrine.” The Truman Doctrine of “containment” was the concept that they must “contain” communism only where it already exists and prevent growth and development past that. He asked for Americans to make sacrifices for it. In the same year, George Marshall tells Harvard graduates that they’re prepared to finance Europe to rebuild after the destruction from World War II, and to contain communism, as the Truman Doctrine states. This was called the Marshall Plan. Marshall believed that communism breeds and grows in poverty, and West Europe, in poverty, would fall vulnerable and possibly fall into communism, so they wanted to grow the economy.
After World War II, Germany was divided into four zones, the Soviet Union’s zone, France’s zone, the United States’ zone, and the British Zone. Because Berlin is the capital, the capital was also divided into four sectors. However, Berlin was located within the Soviet Union’s zone. This gave Stalin a lot of power over Berlin, and he felt as if he was wasting food for the other sectors that were not his, so he decided he would cut transportation for food for the other sectors completely. Churchill decided to send aircrafts with food and clothes to give to them, often celebrated by the people living within the Allies’ sectors of Berlin. Stalin gave up only within a little over 400 days of doing this. This is called the Berlin Airdrift in 1948.
In 1949, many countries came together to form the NATO, which still exists today. It states that if one country of the NATO is attacked by another country outside of the NATO, the other NATO members help. Stalin saw this as a threat to the Soviet Union, so he created the Warsaw Pact, which is a Soviet version of NATO. Because of this, the entirety of Europe is officially fully militarized, not helping the tensions between the United States and Soviet Union.
The tensions did not stop, North Korea invaded South Korea quickly, shockingly, and suddenly. Furthermore, they were using Soviet weapons, cars, trucks, artillery, planes, ships, equipment, etc. North Korea became a proxy of the Soviet Union, and the United States joined the Korean War as an ally of South Korea. Right after, China joined the Korean War, further bringing tensions. The war ended in a stalemate in 1953, however, technically, the war is still going, making the North and South Korean borders the most dangerous in the world.
In 1953, Stalin died. Khrushchev takes the reins, and takes over in 1956. Khrushchev, at first, seems different. In a speech, he announces that Stalin committed crimes against his own people. He promises a more gentle, compassionate communism to the people. Khrushchev brutally ends the Hungarian Revolution. This was a message that he was not about to let the Warsaw Pact nations leave, he was determined to keep the Soviet Union tight.
Back in Berlin, Khrushchev faced an issue. East Berlin was occupied by the Soviet, and the Western Berlin was occupied by the U.S., French, and the British, as was noted before. The Eastern Berliners are leaving Eastern Berlin to go to the west and stay there. This makes Khrushchev angry—so he militarizes Berlin and builds the Berlin Wall in 1961.
Meanwhile, in Cuba, there was a Cuban revolutionary, Fidel Castro, who wanted to establish communism in Cuba. However, Cuba was much too close to the United States’ for their comfort, only 90 miles from U.S. shores. This became the 1962 Cuban Missile Crisis. The leaders of the U.S. and the Soviet Union, for thirteen days, installed stronger and stronger nuclear missiles on Cuba, creating a nuclear arms race. This was close to becoming a war, however, both sides agreed that this would be bad for them. The Soviet Union and U.S. agreed to deescalate the race of nuclear arms, with the Test Ban Treaty.