To what Extent were Soviet Policies Responsible for the Outbreak and Development of the Cold War between 1945, 1949?

The orthodox school sees the Cold War as the product of the aggressive and expansionist foreign policies of USSR. This view has been presented by historians such as W. H .McNeill, H. Feis, and A. Schlesinger.
After WW2 a power vacuum was left in a large part of central and Eastern Europe. Stalin took the advantage of this in order to strengthen the Soviet Union and spread communism. In the Yalta conference (Feb 1945), Stalin demanded parts of Poland to be given to USSR. Stalin made a communist government of Poland although there was already a Polish government in UK. …