It went to a national security adviser, Zbigniew Brzezinski, who was awakened on 9 November 1979, to be told that the North American Aerospace Defense Command (NORAD), the combined U.S.–Canada military command–was reporting a Soviet missile attack. Just before Brzezinski was about to call President Carter, the NORAD warning turned out to be a false alarm. It was one of those moments in Cold War history when top officials believed they were facing the ultimate threat. The apparent cause? The routine testing of an overworked computer system.

source: grugq