1. 1950s and 1960s
    5 November 1956  5 October 1960  24 November 1961  27 October 1962  9 November 1965  23 May 1967 

2. 1970s and 1980s
    9 November 1979  15 March 1980  26 September 1983 

3. Post-Cold War
    25 January 1995 

4. See also

5. References

A nuclear close call is an incident that could lead to, or could have led to, at least one unintended nuclear detonation/explosion. These incidents typically involve a perceived imminent threat to a nuclear-armed country which could lead to retaliatory strikes against the perceived aggressor. The damage caused by international nuclear exchange is not necessarily limited to the participating countries, as the hypothesized rapid climate change associated with even small-scale regional nuclear war could threaten food production worldwide—a scenario known as nuclear famine.^[1]

Despite a reduction in global nuclear tensions after the end of the Cold War, estimated nuclear warhead stockpiles total roughly 15,000 worldwide, with the United States and Russia holding 90% of the total.^[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. At an international level, this includes the importance of context and outside mediation; at the national level, effectiveness in government communications, and involvement of key decision-makers; and, at the individual level, the decisive role of individuals in following intuition and prudent decision-making, often in violation of protocol.^[3]

1950s and 1960s

5 November 1956

During the Suez Crisis, the North American Aerospace Defense Command (NORAD) received a number of simultaneous reports, including unidentified aircraft over Turkey, Soviet MiG-15 fighters over Syria, a downed British Canberra medium bomber, and unexpected maneuvers by the Soviet Black Sea Fleet through the Dardanelles that appeared to signal a Soviet offensive. Considering previous Soviet threats to utilize conventional weapons against France and the UK, U.S. forces believed these events could trigger a NATO nuclear strike against the Soviet Union. In fact, all reports of Soviet action turned out to be erroneous, misinterpreted, or exaggerated. The perceived threat was due to a coincidental combination of events, including a wedge of swans over Turkey, a fighter escort for the Syrian president returning from Moscow, a British bomber brought down by mechanical issues, and scheduled exercises of the Soviet fleet.^[4]

5 October 1960

Radar equipment in Thule, Greenland mistakenly interpreted a moonrise over Norway as a large-scale Soviet missile launch. Upon receiving a report of the supposed attack, NORAD went on high alert. However, doubts about the authenticity of the attack arose due to the presence of Soviet leader Nikita Khrushchev in New York as head of the USSR's United Nations delegation.^[5][6][7]

24 November 1961

Staff at the Strategic Air Command Headquarters (SAC HQ) simultaneously lost contact with NORAD and multiple Ballistic Missile Early Warning System sites. Since these communication lines were designed to be redundant and independent from one another, the communications failure was interpreted as either a very unlikely coincidence or a coordinated attack. SAC HQ prepared the entire ready force for takeoff before already-overhead aircraft confirmed that there did not appear to be an attack. It was later found that the failure of a single relay station in Colorado was the sole cause of the communications problem.^[5]

27 October 1962

At the height of the Cuban Missile Crisis, Soviet patrol submarine {{ship|Soviet submarine|B-59||2}} almost launched a nuclear-tipped 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.^[8] {{USS|Beale|DD-471|6}} began dropping practice depth charges to signal B-59 to surface, however the Soviet submarine took these to be real depth charges.^[9] With low batteries affecting the submarine's life support systems and without orders from Moscow, the commander of B-59 believed that war may have already begun and ordered the use of a 10-kiloton nuclear torpedo against the American fleet. The submarine political officer agreed, but commander of the sub-flotilla Vasili Arkhipov persuaded the captain to surface and await orders.^[10][11]

On the same day, an American U-2 spy plane was shot down over Cuba, and another U-2 flown by United States Air Force Captain Charles Maultsby strayed {{convert|300|mi|km}} into Soviet airspace. Despite orders to avoid Soviet airspace by at least {{convert|100|mi|km}}, a navigational error took the U-2 over the Chukotka Peninsula, causing Soviet MiG interceptors to scramble and pursue the aircraft.^[4][12] 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.^[13] Individual pilots were capable of arming and launching their missiles.

9 November 1965

The Command Center of the Office of Emergency Planning went on full alert after a massive power outage in the northeastern United States. Several nuclear bomb detectors—used to distinguish between regular power outages and power outages caused by a nuclear blast—near major U.S. cities malfunctioned due to circuit errors, creating the illusion of a nuclear attack.^[4]

23 May 1967

A powerful solar flare accompanied by a coronal mass ejection interfered with multiple NORAD radars over the Northern Hemisphere. This interference was initially interpreted as intentional jamming of the radars by the Soviets, thus an act of war. A nuclear bomber counter-strike was nearly launched by the U.S.^[14]

1970s and 1980s

9 November 1979

A computer error at NORAD headquarters led to alarm and full preparation for a nonexistent large-scale Soviet attack.^[5] 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.^[15] Strategic Air Command was notified, and nuclear bombers prepared for takeoff. Within six to seven minutes of the initial response, satellite and radar systems were able to confirm that the attack was a false alarm.^[16][7] It was found that a training scenario was inadvertently loaded into an operational computer. 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."^[15] In the months following the incident there were 3 more false alarms at NORAD, 2 of them caused by faulty computer chips.^[5]

15 March 1980

One of four Soviet missiles launched from a submarine near the Kuril Islands was detected by an American early warning sensor and determined to be heading towards the United States.^[5]

26 September 1983

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. Soon after, it reported that five missiles had been launched. Convinced that a real American offensive would involve many more missiles, Lieutenant Colonel Stanislav Petrov of the Air Defense Forces refused to acknowledge the threat as legitimate and continued to convince his superiors that it was a false alarm until this could be confirmed by ground radar.^{[7][17][18][19][20][21][22][23][24]} Two months later, parts of the Soviet government misinterpreted the Able Archer 83 NATO simulation of escalation to DEFCON 1 as a possible ruse of war to obscure preparations for a genuine nuclear first strike.^[25]

Post-Cold War

25 January 1995

Russian President Boris Yeltsin became the first world leader to activate a nuclear briefcase after Russian radar systems detected the launch of a Norwegian Black Brant XII research rocket being used to study the Northern Lights.^[26] Russian strategic ballistic missile submarines were put on alert in preparation for a possible retaliatory strike.^[27] 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.^[5]

See also

• Sino-Soviet border conflict
• List of military nuclear accidents
• Nuclear and radiation accidents and incidents
• Nuclear winter
• Nuclear terrorism
• Mutually assured destruction
• Vulnerability of nuclear plants to attack
• Cold War II
• World War III

References

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