Between 1945 and 1949, a number of events led the two superpowers to oppose eachother.
Winston Churchill gave a speech in Fulton, Missouri, expressing his growing concern about the rift between the Soviets and the West.
The Communist People's Liberation Army and anticommunist forces were fighting each other for control of Greece in 1946.
Harry S. Truman alarmed by the British withdrawal and the possibility of Soviet expansion into the eastern Mediterranean, responded in the early 1947 with the Truman Doctrine.
In 1947 the split in Europe and the US had vecome a fact of life.
The Truman doctrine was followed in June 1947 by the European Recovery Program.
In July 1947, George Kennan, a well-known US diplomat with crucial knowledge if Soviet affairs, argued for a policy of containment to keep communism within it's existing boundaries and prevent future Soviet aggressive moves.
In 1949, the Soviet Union responded to the Marshall plan by founding the Council for Mutual and Economic Assistance for the economic operation of the US.
By February 1948, Great Britain, France, and the US were making plans yo unify the three western sections of Germany and create a west German government.
The Soviets, who also wanted to avoid war, finally gave in and lifted the blockade on May 1949.
In September 1949, the Federal Republic of Germany, or West Germany, was formally created.
In 1949, Chinese communist took control of the government of China, strengthening the US fears about the spread of Communism.
The Soviets exploded their first atomic bomb in 1949.
The North Atlantic treaty Organization was formed in April 1959, when Belgium, france, the Netherlands, Great Britain,italy, Denmark, Norway, Portugal, and Iceland, signed a treaty with the United States and Canada.
The Korean War began in 1950.
In 1955, the Soviet Union joined with Albania, Bulgaria, Czechoslovakia, East Germany, Hungary, Poland, and Romania in a formal military alliance known as the Warsaw Pact.
In 1957, the Soviets sent Sputnik I, the first human-made space satellite, to orbit the earth.
In 1955 a new leader, Nikita Khrushchev, tried to take advantage of the American concern over missiles.
In August 1961, the East German government began to build a wall separating East Berlin from West Berlin.
In 1959, a left-wing revolutionary named Fidel Castro overthrew the Cuban dictator Fulgencio Batista and set up a Soviet-supported totalitarian regime in Cuba.
In October 1962, Kennedy found out that Soviet ships carrying missiles were headed to Cuba.
A hotline communications system between Moscow and Washington, D.C., was installed in 1963.
In 1964, under President Lyndon B. Johnson, increasing numbers of US troops were sent to Vietnam.
In 1973, President Nixon reached an agreement with North Vietnam's leaders that allowed the United States to withdraw it's armed forces.