February 13 - The first French nuclear test occurs at Reganne, Algeria, in the Sahara Desert. It has a yield of 60-70 kilotons. July 20 - The United States submarine USS George Washington successfully launches a Polaris missile from underwater. November 15 - USS George Washington and its 16 Polaris A1s begin their first patrol. U.S. deploys the Atlas and Titan ICBMs.
1961
February 1 - U.S. launches the Minuteman I missile. September 1 - U.S.S.R. resumes nuclear testing. September 15 - U.S. resumes nuclear testing. October 31 - U.S.S.R. explodes the world's largest nuclear bomb, with a yield of 58 megatons.
1962
July 6 - Project Sedan, a Plowshare Program test, is conducted; formed a 1,280-foot diameter by 320 foot deep crater. July 8 - Electromagnetic pulse from high-altitude nuclear test turns off street lights in Oahu, Hawaii. October 16-28 - The Cuban Missile Crisis occurs. The closest the world has ever come to nuclear war.
1963
June 20 - The U.S. and U.S.S.R. sign the 'hot line' agreement. August 5 - Limited Test Ban Treaty signed by the U.S., U.S.S.R. and the U.K., prohibiting tests of nuclear devices in the atmosphere, in outer space, and underwater.
1964
October 16 - China explodes its first atomic bomb at the Lop Nur test site. It was an uranium 235 implosion fission device named "596" and has a yield of 22 kilotons.
1966
January 17 - U.S. B-52 bomber crashes near Palomares, Spain with four unarmed hydrogen bombs. All four bombs are recovered. September 24 - First French atomic bomb tested at Muruoa Atoll. U.S. Minuteman ICBM enters service.
1967
January 27 - Outer Space Treaty bans nuclear weapons being placed on any celestial body, or in orbit around the Earth. February 14 - Treaty of Tlatelolco signed, creates a Latin America nuclear-weapons-free zone. June 17 - First hydrogen bomb test by the Chinese, with a yield of 3.3 megatons.
1968
July 1 - Non-Proliferation Treaty opened for additional signatures. August 24 - France tests its first hydrogen bomb at Fangataufa Atoll in the South Pacific. It has a yield of 2.6 megatons.
1969
March 14 - President Richard M. Nixon announces the decision to deploy a missile defense system called "Safeguard" to protect U.S. ICBM fields from attack. November to December - Preliminary Strategic Arms Limitation Treaty (SALT) talks take place in Helsinki, Finland.