The Cold War By annstone Feb 4, 1945 Yalta Conference Aug 6, 1945 United States first used atomic bomb in war. Aug 8, 1945 Russia enters war against Japan. Aug 14, 1945 Japanese surrenders, ending WW ll 1946 Winston Churchill delivers "Iron Curtain" speech 1947 Truman announces Truman Doctrine 1947 Marshall Plan is announced 1948 Communists takeover in Czechoslovakia 1948 NATO treaty ratified Jun 24, 1948 Berlin blockade begins 1949 NATO treaty ratified May 12, 1949 Berlin blockade ends