Short answers, pulled from the story.
British Prime Minister Winston Churchill declared that an iron curtain had descended across the continent on the 5th of March 1946. This speech marked a turning point where political rhetoric began to define global alliances with sharp ideological labels.
Twelve countries signed the North Atlantic Treaty on the 4th of April 1949 forming NATO as the alliance's military backbone. Article 5 stated that an attack on one member would be regarded as an attack on all members collectively.
Greece and Turkey received aid first under the policy which would define foreign strategy for decades. The doctrine pledged military and economic assistance to nations threatened by communist subversion beginning in 1947.
Over $13 billion in U.S. aid helped Western Europe recover economically from the devastation of World War II. This sum equates to approximately $150 billion in modern currency when adjusted for inflation.
The Warsaw Pact formed by the Soviet Union in 1955 responded to NATO's expansion particularly after West Germany joined in that same year. This pact formalized the East-West military divide that defined the Cold War period for nearly four decades.