To an extent, the Cold War developed a momentum of its own, as can be seen through a time line of the era.

  • January 5, 1946: President Truman indicates that the US will not recognize future communist governments, since "I'm sick of babying the Soviets" 
  • February 9, 1946: Before the Communist Party Congress, Stalin suggests that communism and capitalism were incompatible.
  • February 22, 1946: George Kennan's Long Telegram, one of the most famous documents of the Cold War, contending that Russian behavior was determined by a "traditional and instinctive Russian sense of insecurity," and that "we have here a political force committed fanatically to the belief that with US there can be no permanent modus vivendi."
  • March 5, 1946: Former British prime minister Winston Churchill, at Fulton, Missouri, declares that an "Iron Curtain" has descended on Europe.
  • March 10, 1946: Truman demands Russia withdraw from Iran, which had been jointly occupied by the British and the Red Army during World War II, with no oil concessions and no annexation of Azerbaijan.
  • September 12, 1946: Former Vice President and then Secretary of Commerce Henry Wallace delivers a Madison Square Garden speech announcing ""the tougher we get with Russia, the tougher they will get with us"; he was forced to resign as Secretary of Commerce September 20.
  • March 12, 1947: President Truman announces the Truman Doctrine, informing Congress, "I believe that it must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures." 
  • June 5, 1947: Secretary of State George Marshall, in a commencement address at Harvard University, announces a package of economic assistance to aid in European recovery. Though not "directed not against any country or doctrine but against hunger, poverty, desperation and chaos," the Marshall Plan further divides Europe into two spheres of influence.
  • July 26, 1947: Congress passes the National Security Act, which creates a civilian Secretary of Defense (the first was James Forrestal), a National Security Council, a Central Intelligence Agency--but does not call for universal military training.
  • February 25, 1948: Communists overthrow the government of Eduard Beneš in Czechoslovakia, the last democratic nation in the Soviet bloc.
  • June 24, 1948: Further increasing tensions over Europe's future, the Soviets begin a blockade of the Western zones in occupied Berlin; the Allied powers would respond with an 11-month airlift to supply the beleaguered city.
  • Apr. 4, 1949: The NATO treaty is signed.
  • July 14, 1949: The USSR explodes its first atomic bomb.
  • Oct. 1, 1949: The Communist Party completes its triumph in the Chinese Civil War, as Mao Zedong assumes power.
  • January 1950: Truman announces that the United States will build the hydrogen bomb.
  • June 1950: North Korea invades South Korea; the UN invokes its collective security provisions to aid the South; and the United States send troops. The war will end in stalemate nearly three years later.
  • Fiscal Year 1951: With the implementation of NSC 68 (see assignment one), U.S. military spending skyrockets.
  • January 1953: Republican Dwight Eisenhower replaces Truman as President; implements a new national security policy, NSC 162/2 (see assignment one), which calls for increased reliance on nuclear weapons and covert activities and decreased overall military spending.
  • March 1953: Soviet dictator Josef Stalin dies; after a protracted power struggle, is eventually replaced by Nikita Khrushchev.
  • June 1954: A U.S.-sponsored coup topples the left-leaning democratically elected government of Guatemala.
  • July 1954: The Geneva Accords recognize the independence of communist North Vietnam and non-communist South Vietnam; elections to reunify the country, which are never held, are scheduled for 1956.
  • November 1956: Soviet troops invade Hungary to topple a neutralist regime that had assumed power after anti-communist protests.
  • January 1959: Fidel Castro assumes power in Cuba. Within 18 months, Castro will have proclaimed himself a Marxist and severed relations with the United States.
  • January 1961: Democrat John Kennedy replaces Eisenhower as President; delivers Inaugural Address promising to aggressively confront the Soviet Union through a variety of tactics.
  • April 1961: An invasion of Cuba by U.S.-sponsored Cuban exiles ends disastrously at the Bay of Pigs.
  • August 1961: Seeking to stem the tide of refugees from communist East Germany into non-communist West Berlin, Nikita Khrushchev authorizes construction of the Berlin Wall.
  • October 1962: The world seems to come to the brink of nuclear war with the Cuban Missile Crisis.
  • 1963: Kennedy dramatically raises the U.S. role in South Vietnam, both by increasing the number of troops in the country and by approving a U.S.-sponsored coup that toppled the government of South Vietnamese leader Ngo Dinh Diem.