Able Archer 83 was a military exercise conducted by NATO that took place in November 1983, as part of the annual Able Archer exercise. It simulated a period of heightened nuclear tensions between NATO and the Warsaw Pact, leading to concerns that it could have been mistaken for a real attack by the Soviet Union. The exercise is considered by some to be one of the closest moments the world came to nuclear war during the Cold War. The purpose of the exercise, like previous years, was to simulate a period of conflict escalation, culminating in the U.S. military attaining a simulated DEFCON 1 coordinated nuclear attack. The five-day exercise, which involved NATO commands throughout Western Europe, was coordinated from the Supreme Headquarters Allied Powers Europe (SHAPE) headquarters in Casteau, Belgium.

The 1983 exercise, which began on November 7, 1983, introduced several new elements not seen in previous years, including a new, unique format of coded communication, radio silences, and the participation of heads of government. This increase in realism, combined with tense relations between the United States and the Soviet Union and the anticipated arrival of Pershing II nuclear missiles in Europe, led some members of the Soviet Politburo and military to believe that Able Archer 83 was a ruse of war, obscuring preparations for a genuine nuclear first strike.Andrew and Gordievsky, Comrade Kryuchkov's Instructions, 85–7.Beth Fischer, Reagan Reversal, 123, 131.Pry, War Scare, 37–9. In response, the Soviet Union readied their nuclear forces and placed air units in East Germany and Poland on alert.Oberdorfer, A New Era, p. 66.SNIE 11–10–84, "Implications of Recent Soviet Military-Political Activities", Central Intelligence Agency, May 18, 1984. The Soviet 4th Air Army began loading nuclear warheads onto combat planes in preparation for war. The apparent threat of nuclear war ended when U.S. lieutenant general Leonard H. Perroots advised against responding to the Warsaw Pact military activity, which ended with the conclusion of the exercise on November 11.Andrew and Gordievsky, Comrade Kryuchkov's Instructions, 87–8.Pry, War Scare, 43–4.

The exercise attracted public attention in 2015 when the President's Intelligence Advisory Board's 1990 report on the exercise was declassified. Some scholars have argued that Able Archer 83 was one of the times when the world has come closest to nuclear war since the Cuban Missile Crisis in 1962. The declassification of related documents in 2021 supported this notion. Other scholars have disputed this.

Prelude to NATO exercise

Operation RYAN

The greatest catalyst to the Able Archer war scare occurred more than two years earlier. In a May 1981 closed-session meeting of senior KGB officers and Soviet leaders, General Secretary Leonid Brezhnev and KGB chairman Yuri Andropov bluntly announced that the United States was preparing a secret nuclear attack on the USSR.

To combat this threat, Andropov announced, the KGB and GRU military foreign intelligence arm would begin Operation RYaN. RYaN () was a Russian acronym for 'nuclear missile attack' (, ); Operation RYaN was the largest, most comprehensive peacetime intelligence-gathering operation in Soviet history. Agents abroad were charged with monitoring the figures who would decide to launch a nuclear attack, the service and technical personnel who would implement the attack, and the facilities from which the attack would originate. It is possible that the goal of Operation RYaN was to discover the first intent of a nuclear attack and then preempt it.Fischer, Benjamin B. (1997). A Cold War Conundrum: The 1983 Soviet War Scare – Phase II: A New Sense of Urgency . CIA.Andrew and Gordievsky, Comrade Kryuchkov's Instructions, 74–76, 86.

The exact impetus for the implementation of Operation RYaN is not known for sure. Oleg Gordievsky, the highest-ranking KGB official ever to defect, attributed it to "a potentially lethal combination of Reaganite rhetoric and Soviet paranoia". Gordievsky conjectured that Brezhnev and Andropov, who "were very, very old-fashioned and easily influenced ... by Communist dogmas", truly believed that an antagonistic Ronald Reagan would push the nuclear button and relegate the Soviet Union to the literal "ash heap of history".Fischer, "A Cold War Conundrum": Appendix A: RYAN and the Decline of the KGB .Testimony of Oleg Gordievsky to Congress. Central Intelligence Agency historian Benjamin B. Fischer lists several concrete occurrences that likely led to the birth of RYaN. The first of these was the use of psychological operations (PSYOP) that began soon after Reagan took office.

In his report, Fischer also writes that another CIA source was, at least partially, corroborating Gordievsky's reporting. This Czechoslovak intelligence officer—who worked closely with the KGB on RYaN—"noted that his counterparts were obsessed with the historical parallel between 1941 and 1983. He believed this feeling was almost visceral, not intellectual, and deeply affected Soviet thinking."

Psychological operations

Psychological operations by the United States began in mid-February 1981 and continued intermittently until 1983. These included a series of clandestine naval operations that stealthily accessed Soviet territorial waters in the far north and far east, demonstrating how close NATO ships could get to critical Soviet military bases. In 1981, a group of 83 American, British, Canadian, and Norwegian ships led by sailed through the Greenland–Iceland–United Kingdom (GIUK) gap undetected by Soviet radar and spy satellites, reaching the Kola Peninsula. There were other operations routinely occurring in the Barents, Norwegian, Black, and Baltic seas. US intelligence ships were regularly posted off the coast of the Crimean Peninsula. American bombers also flew directly towards Soviet airspace, peeling off at the last moment, sometimes several times per week. These near-penetrations were designed to test Soviet radar vulnerability as well as demonstrate US capabilities in a nuclear war.Peter Schweizer, Victory: The Reagan Administration's Secret Strategy That Hastened the Collapse of the Soviet Union (New York: The Atlantic Monthly Press, 1994), p. 8, as quoted at Fischer, "A Cold War Conundrum" (CIA Centre for the Study of Intelligence, 2007) . Retrieved on May 18, 2013.

"It really got to them," said Dr. William Schneider, [former] undersecretary of state for military assistance and technology, who saw classified "after-action reports" that indicated U.S. flight activity. "They didn't know what it all meant. A squadron would fly straight at Soviet airspace, and other radars would light up and units would go on alert. Then at the last minute the squadron would peel off and return home."

FleetEx '83

In April 1983, the U.S. Pacific Fleet conducted FleetEx '83-1, the largest fleet exercise held to date in the North Pacific.Johnson, p. 55Richelson, p. 385 The conglomeration of approximately 40 ships with 23,000 crewmembers and 300 aircraft was arguably one of the most powerful naval armadas ever assembled. US aircraft and ships moved counterclockwise from the Aleutian Islands towards the Kamchatka Peninsula to provoke the Soviets into reacting, allowing the US Office of Naval Intelligence to study Soviet radar characteristics, aircraft capabilities, and tactical maneuvers. The armada conducted operations in areas patrolled by Soviet SSBN's stationed in the strategic Soviet Navy base in Petropavlovsk. On April 4 at least six U.S. Navy F-14 Tomcat fighters from and flew over a Soviet military base in Zeleny Island, one of the Kuril Islands, in a simulated bombing raid. In retaliation the Soviets ordered an overflight of the Aleutian Islands. The Soviet Union also issued a formal diplomatic démarche of protest, which accused the United States of repeated penetrations of Soviet airspace.1983: The most dangerous year by Andrew R. Garland, University of Nevada, Las Vegas In a testimony to the Senate Armed Services Committee, Chief of Naval Operations James D. Watkins said that the Soviet Union was "as naked as a jaybird [on the Kamchatka Peninsula], and they know it".

Korean Air Lines Flight 007

On September 1, 1983, Korean Air Lines Flight 007 (KAL 007) was shot down by a Soviet Su-15 interceptor over the Sea of Japan near Moneron Island (just west of Sakhalin island) while flying over prohibited Soviet airspace. All 269 passengers and crew aboard were killed, including Larry McDonald, a sitting member of the United States House of Representatives from Georgia and president of the anti-communist John Birch Society.

Weapons buildup From the start, the Reagan administration adopted a bellicose stance toward the Soviet Union, one that favored seriously constraining Soviet strategic and global military capabilities. The administration's focus on this objective resulted in the largest peacetime military buildup in the history of the United States. It also ushered in the final major escalation in rhetoric of the Cold War. On June 8, 1982, Reagan, in a speech to the British House of Commons, declared that "Freedom and democracy will leave Marxism and Leninism on the ash heap of history."

On March 23, 1983, Reagan announced one of the most ambitious and controversial components to this the Strategic Defense Initiative (labeled "Star Wars" by the media and critics). While Reagan portrayed the initiative as a safety net against nuclear war, leaders in the Soviet Union viewed it as a definitive departure from the relative weapons parity of détente and an escalation of the arms race into space. Yuri Andropov, who had become General Secretary following Brezhnev's death in November 1982, criticised Reagan for "inventing new plans on how to unleash a nuclear war in the best way, with the hope of winning it".Fischer, A Cold War Conundrum: "Star Wars"

Despite the Soviet outcry over the Strategic Defense Initiative, the weapons plan that generated the most alarm among the Soviet Union's leadership during Able Archer 83 was NATO's planned deployment of intermediate-range Pershing II missiles in Western Europe. These missiles, deployed to counter Soviet RSD-10 Pioneer intermediate-range missiles on the USSR's western border, represented a major threat to the Soviets. The Pershing II was capable of destroying Soviet "hard targets" such as underground missile silos and command and control bunkers.Andrew and Gordievsky, Comrade Kryuchkov's Instructions, 74–76.

The missiles could be emplaced in and launched from any surveyed site in minutes, and because the guidance system was self-correcting, the missile system possessed a genuine first strike capability. Furthermore, it was estimated that the missiles (deployed in West Germany) could reach targets in the western Soviet Union within four to six minutes of their launch. These capabilities led Soviet leaders to believe that the only way to survive a Pershing II strike was to preempt it. This fear of an undetected Pershing II attack, according to CIA historian Benjamin B. Fischer, was explicitly linked to the mandate of Operation RYaN: to detect a decision by the United States to launch a nuclear attack and to preempt it.

False alarm from the Soviet missile early warning system

On the night of September 26, 1983, the Soviet orbital missile early warning system (SPRN), code-named Oko, reported an intercontinental ballistic missile launch from the territory of the United States.Schmalz, pp. 28–29 Lieutenant Colonel Stanislav Petrov, who was on duty during the incident, dismissed the warning as a computer error when ground early warning radars did not detect any launches. Part of his reasoning was that the system was new and known to have malfunctioned previously; also, a full-scale nuclear attack from the United States would involve thousands of simultaneous launches, not a single missile.