May 26, 1972 (, Yam Tze April 14), the United States and the Soviet Union to limit strategic nuclear weapons agreement was signed. In early

1964, the United States to the Soviet Union on strategic arms limitation talks. October 25, 1969, the two sides reached an agreement, the talks in Helsinki on November 17, 1969. On 26,
1972 the United States and the Soviet Union heads of state on the Limitation of Anti-Ballistic Missile Treaty, "and some of the measures on the limitation of strategic offensive weapons Interim Agreement" and a series of supplementary agreement signed in Moscow books, collectively referred to as the first phase of the Strategic Arms Limitation Treaty.
provisions of the treaty to their respective capitals for the center, within a radius of 150 kilometers, the two sides can be deployed to more than 100 anti-ballistic missile and six ABM radar; near Chau anti-missile bases in a radius of 150 km, can be deployed not more than 100 anti-ballistic missile, two large-scale anti-ballistic missile radar and 18 smaller radar. Treaty as valid indefinitely. (History TodayOnHistory.com)