Basically, Truman doctrine is a foreign policy made by Henry Truman that rejects all of Soviet geopolitical movements. As shown by his support towards Greece and Turkey as well as his famous doctrine speech.
What is the Truman Doctrine?
Through the speech Truman said, the USA therefore has rejected the Idea of isolationism. He just announced that the USA would play a leading part as well in the world politics. In Greece and Turkey, the doctrine was proven to be successful as the communist side was defeated in the Greek Civil War. The Doctrine was then applied to Europe and Middle east. It expanded to the whole world eventually, which led to a war in Korea and Vietnam.
The Marshall Plan
The Marshall Plan is a belief created in Washington in which that communism can only be stopped if Western Europe became wealthy, and without the help of the USA at that time, there is a little chance of economic recovery. So they decided to offer massive economic aid to Western Europe. The Communist side was able to help technically, but Stalin viewed it as an attempt to put capitalist ideas on European countries, which he is correct about. So he refused. The Plan was based on a belief that communism would be much less attractive to ordinary people if they had better jobs and is well paid. The Plan was a great success, as over a period of 4 years, $13.000 million of help was provided and European countries were encouraged to reduce import taxes which increased the level of trade. By rebuilding Western Europe, America was creating wealthy trade partners who would like to buy large sum of American Goods.
The Soviet Response The Soviets responded with an international conference in September 1947 in order to condemn the Truman Doctrine and the Marshall Plan. Also, a new organisation was set up to strengthen links between communist parties in different countries called Com inform. Communist parties in Western Countries were ordered to wreck the Marshall Plan through strikes. However, the strikes did not work. Since the strikes did not work, the USSR created a new economic bloc of countries in Eastern Europe. So, in January 1949, the Comecon was formed. Though it was not as succesful as the Marshall Plan as it did not involve any injection of money