[2] Though exact details on many nuclear close calls are hard to come by, the analysis of particular cases has highlighted the importance of a variety of factors in preventing accidents.
The perceived threat was due to a coincidental combination of events, including a wedge of swans over Turkey, a fighter escort for Syrian President Shukri al-Quwatli returning from Moscow, a British bomber brought down by mechanical issues, and scheduled exercises of the Soviet fleet.
Due to safety measures the plutonium core was not mounted to the bomb at the time but rather stored elsewhere in the plane, preventing a nuclear detonation.
This was an ultimately failed preemptive strike prior to an attempted invasion of Taiwan, where the Republic of China's (ROC) military forces and political apparatuses, known as the Kuomintang (KMT), had been exiled since the end of the Chinese Civil War in 1949.
However, doubts about the authenticity of the attack arose due to the presence of Soviet leader Nikita Khrushchev in New York City as head of the USSR's United Nations delegation.
"[15] An expert evaluation written on 22 October 1969 by Parker F. Jones, the supervisor of the nuclear weapons safety department at Sandia National Laboratories, reported that "one simple, dynamo-technology, low voltage switch stood between the United States and a major catastrophe", and that it "seems credible" that a short circuit in the Arm line during a mid-air breakup of the aircraft "could" have resulted in a nuclear explosion.
Staff at the Strategic Air Command Headquarters (SAC HQ) simultaneously lost contact with NORAD and multiple Ballistic Missile Early Warning System sites.
[10] During the Cuban Missile Crisis, United States military planners expected that sabotage operations might precede any nuclear first strike by the Soviet Union.
The pilots had been told there would be no practice alert drills and, according to political scientist Scott D. Sagan, "fully believed that a nuclear war was starting".
[17][18] Sagan writes that the incident raised the dangerous possibility of an ADC interceptor accidentally shooting down a Strategic Air Command (SAC) bomber.
[17] At the height of the Cuban Missile Crisis, Soviet patrol submarine B-59 almost launched a nuclear torpedo while under harassment by American naval forces.
One of several vessels surrounded by American destroyers near Cuba, B-59 dove to avoid detection and was unable to communicate with Moscow for a number of days.
[20] With low batteries affecting the submarine's life support systems and unable to make contact with Moscow, the commander of B-59 feared that war had already begun and ordered the use of a 10-kiloton nuclear torpedo against the American fleet.
[4][23][24] American F-102A interceptors armed with GAR-11 Falcon nuclear air-to-air missiles (each with a 0.25 kiloton yield) were then scrambled to escort the U-2 into friendly airspace.
Reports on the condition of the bombs varied, with Department of Defense (DoD) saying they were "relatively intact" while Sandia National Laboratories engineers saying they "broke apart" and that it was too risky to hastily move them.
The Command Center of the Office of Emergency Planning went on full alert after a massive power outage in the northeastern United States.
In the early days of the French Strategic Air Forces, electrical transmissions were disrupted due to a thunderstorm, causing a wartime takeoff order to be displayed.
When they reached their refueling zone, they were unable to find the supply plane, forcing them to abort their mission, turn back, and land.
These radars included three Ballistic Missile Early Warning Systems (BMEWS) that had been upgraded, and only resumed operation 8 days prior to the flare.
[4] 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 (IDF) moved to encircle the Egyptian Third Army.
A General Accounting Office investigation found that a training scenario was inadvertently loaded into an operational computer in the Cheyenne Mountain Complex.
"[36] Soviet General Secretary Leonid Brezhnev composed a letter to U.S. President Jimmy Carter that the false alarm was "fraught with a tremendous danger" and "I think you will agree with me that there should be no errors in such matters.
[39] Several weeks after the downing of Korean Air Lines Flight 007 over Soviet airspace, a satellite early-warning system near Moscow reported the launch of one American Minuteman ICBM.
[5][40][41][42][43][44][45][excessive citations] Able Archer 83 was a command post exercise carried out by NATO military forces and political leaders between 7 and 11 November 1983.
In response, Soviet nuclear capable aircraft were fueled and armed ready to launch on the runway, and ICBMs were brought up to alert.
[52] During the Persian Gulf War, Ba'athist Iraq launched Scud missiles at Saudi Arabia and Israel and possessed a large cache of weapons of mass destruction.
At the same time U.S. Secretary of Defense Dick Cheney, General Norman Schwarzkopf Jr., and British Prime Minister Margaret Thatcher all emphasized that the use of WMD against Coalition forces would lead to a nuclear attack on Iraq.
[55] After the war, the Defense Intelligence Agency credited these threats with deterring Iraq from launching chemical attacks on Coalition forces.
As the tornado approached Andover, it struck the McConnell Air Force Base, where it narrowly missed ten lined up Rockwell B-1 Lancers, two of them armed with nuclear warheads.