According to Wikipedia the United States are a signatory state of the Non-Proliferation Treaty, which was signed on 1968-07-01 and came into effect on 1970-03-05. But when did the USA ratify it?


According to the U.S. Dept. of State, various bodies within the U.S. government performed the following steps on the Treaty on the Non-Proliferation of Nuclear Weapons (NPT):

  • Signed at Washington, London, and Moscow July 1, 1968
  • Ratification advised by U.S. Senate March 13, 1969
  • Ratified by U.S. President November 24, 1969
  • U.S. ratification deposited at Washington, London, and Moscow March 5, 1970
  • Proclaimed by U.S. President March 5, 1970
  • Entered into force March 5, 1970

The depositary governments of the NPT are the Russian Federation, United Kingdom of Great Britain and Northern Ireland, and the United States of America.

For details, see:

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