This was the preparatory stage of the cold war. After general hostilities ceased in 1945, the communists selected Italy, France, Greece and Turkey as their main targets. They strengthened their position in France and Italy, by taking advantage of the prevailing chaotic conditions after the World War II.

The Truman Doctrine was announced by President Truman in the American Congress on March 12, 1947. He declared that the United States must adopt a policy to support free peoples who were resisting attempted subjugation by armed minorities or by outside pressures. He said "We must take immediate and resolute action." The Truman Doctrine was a proposal to send military and economic aid to Greece and Turkey, which the American Congress authorized in May 1947.

The Marshall Plan was an extension of the principle underlying the Truman Doctrine. The Secretary of State Marshall initiated the European Recovery Program, through his famous speech at Harvard on June 5, 1947. The Soviet Union attacked the Marshall Plan regarding it as an intervention in the internal affairs of other countries. The tension between the US and the Soviet Union in Greece increased so that relations between them deteriorated. In accordance with the Marshall Plan, the US gave 11 billion dollars in aid within a four-year period. Thus it helped in protecting Europe from economic collapse and communist domination.

The Molotov Plan was initiated by the Soviet Union which also established the Council of Mutual Economic Assistance (COMECON) to help the economic consolidation of socialist countries. Thus the Marshall Plan and the COMECON heralded the "cold war" in international relations between the US and the Soviet Union.