1945 World War II: Hiroshima is devastated when the atomic bomb "Little Boy" is dropped by the United States B-29 ''Enola Gay''. Around 70,000 people are killed instantly, and some tens of thousands die in subsequent years from burns and radiation poisoning.
1953 Cold War: U.S. President Dwight D. Eisenhower formally approves the top secret document National Security Council Paper No. 162/2, which states that the United States' arsenal of nuclear weapons must be maintained and expanded to counter the communist threat.
1962 Cuban Missile Crisis: US President John F. Kennedy, after internal counsel from Dwight D. Eisenhower, announces that American reconnaissance planes have discovered Soviet nuclear weapons in Cuba, and that he has ordered a naval "quarantine" of the Communist nation.
1979 Nuclear false alarm: the NORAD computers and the Alternate National Military Command Center in Fort Ritchie, Maryland detected purported massive Soviet nuclear strike. After reviewing the raw data from satellites and checking the early warning radars, the alert is cancelled.
1981 Cold War: In Geneva, representatives from the United States and the Soviet Union begin to negotiate intermediate-range nuclear weapon reductions in Europe (the meetings ended inconclusively on December 17).