European Recovery Programme (a.k.a. the Marshall Aid Programme) to revive Europe's post-war economies. The Marshall Plan was seen as important in deterring communist aggression in Western Europe, following the alarming consolidation of communist power within many Eastern European governments. In Marshall's speech, it was mentioned that the programme was "directed not against any country or doctrine but against hunger, poverty, desperation and chaos". The US hoped that Eastern European economies would be tempted to take up the aid to weaken the Soviet Union's control.
Though the Soviet Union contemplated taking up US aid, they realized that the need for an open economy, which the aid required, was an unpalatable feature for them. When Czechoslovakia and Poland indicated interest in the aid, the USSR pressured them into rejecting it. Molotov would soon initiate COMECON for the Eastern bloc later on. Yugoslavia would apply for and receive Marshall Aid, after Stalin kicked Tito out from COMINFORM.
The Marshall Plan was an obvious economic success, but this very success caused a crisis in Soviet-Western relations. By the spring of 1948, Europe was firmly divided into two distinct blocs, fulfilling Churchill's prediction of an iron curtain materializing.
The implementation of this plan pushed the Soviet Union towards greater communisation/Sovietisation/Stalinisation of Europe. (1947 was thus a turning point - before 1947, the spirit of maintaining Allied unity enforced the gradual achievement of Europe. It was the Marshall Plan that spurred the Soviets' urgency.) Communist parties in Western Europe were asked to campaign against the Marshall Plan, but this backfired over time as they failed to win significantly in elections and were removed from coalition governments.
In Eastern Europe, countries were forced to adopt Soviet-style planned economies and establish "people's democracies". Non-communists soon found themselves removed from power through "salami tactics":
POLAND - London Poles and Lublin Poles
ROMANIA - heavily rigged elections in 1946
HUNGARY - Ferenc Nagy was compelled to resign in exchange for his son, who was kidnapped by Soviet-backed security apparatus
CZECHOSLOVAKIA - Jan Masaryk was found dead under mysterious circumstances
YUGOSLAVIA - ignored Soviet Union's interests and was thus expelled from COMINFORM, joining the Non-Aligned Movement in 1955