After the Second World War the relationship between super powers, the United States of America and the Soviet Union, became openly hostile with the threat of nuclear war hanging over the world. This hostility lasted for decades and became known as the Cold War. The situation before World War II was not so tense between the tow countries although tension had been rising between them from the 1890's. The power in the USSR had passed from Lenin to Stalin who proposed an independent nation and emphasized the need for social security. It was he who created the buffer zone after World War II using communist countries in an attempt to increase the safety of Russia. This buffer zone was one of the reasons for the dramatic increase in hostility between the two nations as the USA saw this as the spreading of the communist interest and an aggressive move. This is the traditional or orthodox view which feared Soviet or communist expansion. This was widely held during the Cold War in the USA. A contrasting view is the revisionist view which says that the USA was not sufficiently sympathetic to the USSR's security worries after being invaded so may times and because the USSR had ambitions in Eastern Europe, did not mean there were further plans for expansion else where. This was a popular view in the USSR while the Cold War was happening. Now days another view has developed and is called the post-revisionist view. It takes into account new evidence that has come to light and now suggests, "once this complex interaction of stimulus and response is taken into account, it becomes clear that neither side can bear sole responsibility for the onset of the Cold War. - With hindsight it has been easier to gain a balanced opinion as new evidence has come to light such as the opening of the Soviet archives.
The dramatic increase in the tension between the USA and the USSR began after World War II. After the victory high' wore off people in the USA began to become aware of the USSR's moves in Eastern Europe to create a buffer zone.