List of nuclear close calls
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.
Despite a reduction in global nuclear tensions and major nuclear arms reductions 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.
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.
1950s and 1960s
5 November 1956
During the Suez Crisis, the North American Aerospace Defense Command 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 United Kingdom, 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.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 City as head of the USSR's United Nations delegation.24 January 1961
On 24 January 1961, a B-52 Stratofortress carrying two 3–4-megaton Mark 39 nuclear bombs broke up in mid-air near Goldsboro, North Carolina, dropping its nuclear payload in the process. The pilot in command, Walter Scott Tulloch, ordered the crew to eject at. Five crewmen successfully ejected or bailed out of the aircraft and landed safely, another ejected but did not survive the landing, and two died in the crash. Information newly declassified in 2013 showed that one of the bombs came very close to detonating.24 November 1961
Staff at the Strategic Air Command Headquarters 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.27 October 1962
At the height of the Cuban Missile Crisis, Soviet patrol submarine 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. began dropping practice depth charges to signal B-59 to surface; however the captain of the Soviet submarine and its zampolit took these to be real depth charges. 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. The zampolit agreed, but the flotilla commander Vasili Arkhipov, realizing that the use of "toy" depth charges meant the US vessels were only harassing them, not attacking them, refused permission to launch. He convinced the captain to calm down, surface, and make contact with Moscow for new orders.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 into Soviet airspace. Despite orders to avoid Soviet airspace by at least, a navigational error took the U-2 over the Chukotka Peninsula, causing Soviet MiG interceptors to scramble and pursue the aircraft. American F-102A interceptors armed with GAR-11 Falcon nuclear air-to-air missiles were then scrambled to escort the U-2 into friendly airspace. 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.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 United States.1970s and 1980s
October 1973
During the Yom Kippur War, Israeli officials panicked that the Arab invasion force would overrun Israel after the Syrian Army nearly achieved a breakout in the Golan Heights, and the U.S. government rebuffed Israel's request for an emergency airlift. According to a former CIA official, General Moshe Dayan requested and received authorization from Israeli Prime Minister Golda Meir to arm 13 Jericho missiles and 8 F-4 Phantom II fighter jets with nuclear warheads. The missile launchers were located at Sdot Micha Airbase, while the fighter jets were placed on 24-hour notice at Tel Nof Airbase. The missiles were said to be aimed at the 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. 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
A computer error at NORAD headquarters 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, satellite and radar systems were able to confirm that the attack was a false alarm. 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." In the months following the incident there were three more false alarms at NORAD, two of them caused by faulty computer chips.15 March 1980
A Soviet submarine near the Kuril Islands launched four missiles as part of a training exercise. Of these four, American early warning sensors suggested one to be aimed towards the United States. In response, the United States convened officials for a threat assessment conference, at which point it was determined to not be a threat and the situation was resolved.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 to 11 November 1983
Able Archer 83 was a command post exercise carried out by NATO military forces and political leaders between 7 and 11 November 1983. The exercise simulated a Soviet conventional attack on European NATO forces 3 days before the start of the exercise, transitioning to a large scale chemical war and on day 1 of the exercise, NATO forces sought political guidance on the use of nuclear weapons to stem the Soviet advance which was approved by political leaders. NATO then began simulating preparations for a transition to nuclear war.These simulations included 170 radio-silent flights to air lift 19,000 US troops to Europe, regularly shifting military commands to avoid nuclear attack, the use of new nuclear weapon release procedures, the use of nuclear Command, Control, and Communications networks for passing nuclear orders, the moving of NATO forces in Europe through each of the alert phases from DEFCON 5 to DEFCON 1, and the participation of political leaders like Margaret Thatcher, Helmut Kohl and Ronald Reagan.
The issue was worsened by leaders referring to B-52 sorties as "nuclear strikes", by the increased use of encrypted diplomatic channels between the US and UK, and by the nuclear attack false alarm in September.
In response, Soviet nuclear capable aircraft were fuelled and armed ready to launch on the runway, and ICBMs were brought up to alert. Soviet leaders believed the exercise was ruse to cover NATO preparations for a nuclear first strike and frantically sent a telegram to its residencies seeking information on NATO preparations for an attack. The exercise closely aligned with Soviet timeline estimations that a NATO first strike would take 7 to 10 days to execute from the political decision being made.
Soviet forces stood down after 11 November when the exercise ended and NATO was not aware of the complete Soviet response until British intelligence asset Oleg Gordievsky passed on the information.