Greece was under control of the British government attempting to set up free elections, so therefore was in the British sphere of influence. civil war broke out between the traditionalists in 1945 who supported the monarch (British support also) and the communist reformists who attempted to rebel in. the west suggested Stalin had influenced a communist uprising because of commintern, this broke the Atlantic charter because they weren’t politically free. the British were forced to call for help from the US because they were unable to fund a war in Greece, the Truman doctrine was put in place to justify their involvement, saying they had to protect the people of Greece from communist indoctrination. it ended in 1949.
Marshall aid was set up by general Marshall of the US army in 1947 to provide $13 billion in financial aid to European countries. he had been sent to assess the conditions in Europe and concluded that poverty lead to the rise of extremist parties like the communists. their policy of containment meant they would need to end poverty to stop the spread of communism. this was the theory but Stalin had prevented any of the eastern European countries in his sphere of influence from accepting the aid, which meant the aid wouldn’t be preventing communist spread where the Americans had been aiming to stop it. the soviets also declined the aid, because they saw it as America undermining Russia’s power and presenting them as weak to the world, effectively a propaganda campaign. America didn’t see it as that, they simply wanted to mend relations and decrease suspicion; they couldn’t send aid all throughout Europe and miss out one of the most heavily effected nations, that would be disastrous.