about to collapse. 25 January 1995 Russian President Boris Yeltsin became the first world leader to activate the Russian nuclear briefcase after Russian radar systems detected the launch of what was later determined to be a Norwegian Black Brant XII research rocket being used to study the Northern Lights. Russian ballistic missile submarines were put on alert in preparation for a possible retaliatory strike. When it became clear the rocket did not pose a threat to Russia and was not part of a larger attack, the alarm was cancelled. Russia was in fact one of a number of countries earlier informed of the launch; however, the information had not reached the Russian radar operators. See also Broken Arrow (nuclear) Cold War II Doomsday Clock List of military nuclear accidents Mutual assured destruction Nuclear and radiation accidents and incidents Nuclear terrorism Nuclear winter Sino-Soviet border conflict Vulnerability of nuclear plants to attack World War III References Further reading Close calls Close calls Close calls Close calls War scare