After the World War II in 1945, when alliance between the United States, Britain and USSR ended, an intense rivalry emerged between the communist and non-communist nations that result in the Cold War. It is known as cold war because the rivalry never led to armed conflict. However, the rivalry is not the only cause of the cold war and you would want to know what are the major causes of cold war. When the USA decided to drop the atomic bomb on Japan, Hiroshima to be precise, the USSR was upset as they do not know that America is developing the nuclear bomb.
On the other hand, the leaders of each country in the alliance were upset with the USSR president, Stalin as he had already signed a border treaty agreement with Poland. In the year 1948, Russia has conquered half of the Europe and Winston Churchill refer the countries that was conquered by the Russia as an Iron Curtain that divided Europe. The allies were angered that Stalin never keep his promise about the free elections and a new foreign policy of containment to keep communism were to into effect by Stalin.
The Cold War was the result of two different worldviews, the clash between communism and capitalism. Another major cause of Cold War was the intransigent attitude of both sides of the world. The Soviet Union was invaded twice in the twentieth century and was having a great concern about the security of its country. When Russia found out that USA have created and used the atomic bomb against Japan, they too build one atomic bomb for themselves. Soon after the race of who have the most superior weapons, it evolves into a race of who have a better technology.
The technological race was practically the race of who will be able to conquer the space first. The Soviet Union launched Sputnik I on 4th October 1957, the world first orbiting satellite and on 3rd November they launched Sputnik II with a living creature, a dog named Laika and it is the first living creature to go to the space. However, USA managed to show their superiority in technology when Neil Armstrong became the first person to step on the moon.
When Berlin Wall as built in 1961 to separate the two side of German, this has brought more tension to the Cold War and the tension continues for 30 years until in 1990, the Berlin Wall was demolished.