The Cold War emerged from a conflict between Stalin and U.S. President Harry Truman over the future of Eastern Europe during the Potsdam Conference in the summer of 1945 . Russia had suffered three devastating Western onslaughts in the previous 150 years during the Napoleonic Wars , the First World War , and the Second World War , and Stalin 's goal was to establish a buffer zone of states between Germany and the Soviet Union . Truman charged that Stalin had betrayed the Yalta agreement . With Eastern Europe under Red Army occupation , Stalin was also biding his time , as his own atomic bomb project was steadily and secretly progressing
Potsdam Conference
Potsdam Conference
History of Russia