Arab military headquarters in Cairo and Damascus. The United States discovered Israel's nuclear deployment after a Lockheed SR-71 Blackbird reconnaissance aircraft spotted the missiles, and it began an airlift the same day. After the U.N. Security Council imposed a ceasefire, conflict resumed when the Israel Defense Force moved to encircle the Egyptian Third Army. According to former U.S. State Department officials, General Secretary Leonid Brezhnev threatened to deploy the Soviet Airborne Forces against Israeli forces, and the U.S. Armed Forces were placed at DEFCON 3. Israel also redeployed its nuclear weapons. While DEFCON 3 was still in effect, mechanics repairing the alarm system at Kincheloe Air Force Base in Michigan accidentally activated it and nearly scrambled the B-52 bombers at the base before the duty officer declared a false alarm. The crisis finally ended when Prime Minister Meir halted all military action. Declassified Israeli documents have not confirmed these allegations directly, but have confirmed that Israel was willing to use "drastic means" to win the war. 9 November 1979 Computer errors at the NORAD headquarters in Peterson Air Force Base, the Strategic Air Command command post in Offutt Air Force Base, the National Military Command Center in the Pentagon, and the Alternate National Military Command Center in the Raven Rock Mountain Complex led to alarm and full preparation for a nonexistent large-scale Soviet attack. NORAD notified national security adviser Zbigniew Brzezinski that the Soviet Union had launched 250 ballistic missiles with a trajectory for the United States, stating that a decision to retaliate would need to be made by the president within 3 to 7 minutes. NORAD computers then placed the number of incoming missiles at 2,200. Strategic Air Command was notified, and nuclear bombers prepared for takeoff. Within six to seven minutes of the initial response, PAVE PAWS satellite and radar systems were able to confirm that the attack was a false alarm. Congress quickly learned of the incident because Senator Charles H. Percy was present at the NORAD headquarters during the panic. A General Accounting Office investigation found that a training scenario was inadvertently loaded into an operational computer in the Cheyenne Mountain Complex. Commenting on the incident, U.S. State Department adviser Marshall Shulman stated that "false alerts of this kind are not a rare occurrence. There is a complacency about handling them that disturbs me." Soviet General Secretary Leonid Brezhnev composed a letter to U.S. President Jimmy