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

The Cold War starting from 1945 to its end had lasted for 44 years. 44 years of different degrees and stages of tension between the two Superpowers. Who was to blame for the outbreak and development of the Cold War? Both sides were to blame, and the Soviet policies between 1945 and 1949 were, thus, responsible for it to a certain extent.
Economically, the Soviets did not allow its Eastern Bloc to receive the US's Marshall Plan aid, and set up Comecon to oppose it, and these actions by the Soviets increased the tensions between the US and the USSR. …