Cold War
May 7 German surrender.
  July 3 Berlin: Allied troops complete occupation of Berlin.
  July 16 Atomic bomb: first successful test of atomic bomb.
  August Atomic bomb used on Japanese cities of Hiroshima and Nagasaki.
  August 14 Japanese surrender.
  November 5 Elections in Hungary. Communist Party won only 17 percent of the vote. Stalin helped Communists to establish control in Hungary anyway.
  November 29

Yugoslavia became a Communist republic under Marshal Tito.
Iran: America and Britain withdraw their troops from Iran (Persia); Soviet Union troops remain in Iran (1945-1946)

February 28 US Secretary of State James F. Byrnes introduced new "get tough with Russia" policy.
  March 5 Winston Churchill made a speech at Fulton, Missouri. His speech claimed that an "iron curtain" has come down across Europe.
  March 21 Strategic Air Command, Tactical Air Command, and Air Defence Command are created within the American Army Air Forces. These are principally concerned with nuclear bombing.
  June 30 National referendum of Polish population approved Communist reforms in Poland which made Poland a Communist state.
  July 1 Further Atomic bomb tests, using the Nagasaki-type implosion bomb, held at Bikini Atoll in the Pacific.
March 12 Truman Doctrine
  May 31 Hungary is taken over by Communist government.
  June 5 Marshall Plan
  July US announced Containment Policy to block the expansion of Soviet political and economic influence into areas around the world.
  October 29 Israel: The U.N. authorizes the creation of the State of Israel.
  December 30 Eastern Europe: Romania's monarchy is replaced by a Communist regime.
February 25 Communist takeover in Czechoslovakia.
  March 17 Brussels Treaty signed by Belgium, Britain, France, Holland, and Luxembourg created a Atlantic regional mutual-defence treaty, in part a response to the Czechoslovakian crisis.
  April 1 Berlin Blockade began.
  August 3 First of numerous revelations about Soviet spies in US government departments. Most allegations (but not all) were unfounded.