According to Scott Foresman Advanced Dictionary, a cold war is a conflict between nations for national advantage conducted by political, economic, and psychological means instead of direct military action. The Cold War that had broken out by 1950 was a competition for power and it was between the communist, led by the USSR, and the capitalist, led by the USA. After reviewing all the factors, it can be said that both the USA and the USSR had an equal role in setting fire to the Cold War.
One of the first and main reasons why a cold war broke out between the USA and USSR was that at the end of World War II there stood only two continental size leading nations; USA and USSR. Both of them, after World War II, had the same ambition, to have power over half of the world and that was where all the confrontations began as the USSR was not willing to give into USA's domination of Eastern Europe and the USA was not willing to accept the spread USSR's communist power. Both the USA and the USSR wanted to control half of the world as both sides believed that their political and economic systems were better than the other.
Also another cause of the Cold War was the distrust, suspicion and misunderstanding that existed between both the USA and the USSR. Many times the USA accused the USSR of seeking to expand their communist and socialist ideas to the rest of the world. On the other hand, USSR accused the USA of practicing imperialism and for blocking the attempts of revolutionary actions. .
In addition, when USSR joined the USA and Western Europe against Germany it was believed that that was the end of their confrontations. However, that was not the scenario as the USA adopted a "get tough" attitude towards the USSR. The USSR responded to this "get tough" attitude of the USA by accusing the USA and her allies of trying to enclose the USSR in a corner so as to later dispose of its communist government.