The Seabed Treaty enters into force. [see February 11, 1971]
SALT II treaty negotiations begin.
The first round of Strategic Arms Limitation Talks (SALT I ) ends with President Richard M. Nixon and General Secretary Leonid Brezhnev signing the Anti-Ballistic Missile (ABM) Treaty, the SALT Accord, and the Interim Agreement on Strategic Offensive Arms. The ABM Treaty provides that the United States and the Soviet Union may each have only two ABM deployment areas, which are restricted and located in such a way that they cannot provide the basis for a nationwide ABM defense. Each country thus agrees to leave unchallenged the penetration capability of the other country's retaliatory missile forces.
The Anti-Ballistic Missile (ABM) Treaty enters into force.