Document · Treaty · 30 September 1971
US-Soviet Accident Measures Agreement, 1971 (Article 3: unidentified objects)
The Agreement on Measures to Reduce the Risk of Outbreak of Nuclear War, signed in Washington on 30 September 1971 and in force the same day (UN Treaty Series vol. 807, no. 11509). Article 3: "The Parties undertake to notify each other immediately in the event of detection by missile warning systems of unidentified objects, or in the event of signs of interference with these systems or with related communications facilities, if such occurrences could create a risk of outbreak of nuclear war between the two countries." The text does not say UFO. Four years after Malmstrom, both nuclear superpowers put unidentified objects seen by their missile warning systems into a binding rule to call each other at once.