The 1982 Hårsfjärden incident (30 September – 30 October 1982) was a

peace Peace is a state of harmony in the absence of hostility and violence, and everything that discusses achieving human welfare through justice and peaceful conditions. In a societal sense, peace is commonly used to mean a lack of conflict (suc ...

time naval engagement in which the

Swedish Navy The Swedish Navy () is the maritime service branch of the Swedish Armed Forces. It is composed of surface and submarine naval units – the Fleet (), formally sometimes referred to as the Royal Navy () – as well as marine units, the Amph ...

laid a trap for, pursued, and attempted to sink a foreign submarine that had violated Swedish

territorial waters Territorial waters are informally an area of water where a sovereign state has jurisdiction, including internal waters, the territorial sea, the contiguous zone, the exclusive economic zone, and potentially the extended continental shelf ( ...

. The incident came in the wake of increased Soviet submarine activity in the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

, with Sweden alleging that the

Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

had violated Sweden's territorial waters several times from 1974 – 1981. The incident, which led to a parliamentary investigation in Sweden, resulted in increased tensions between Sweden and the Soviet Union, and the claimed intrusion of a Soviet submarine remains a contested topic.

History

Background

Following the development of the

Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...

between the United States and Soviet Union, the government of

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

adopted a stance of armed neutrality, seeking to avoid being pulled into the direct influence of either superpower. Despite this adherence to neutrality, the vast majority of Sweden's military efforts were focused on defending against armed aggression by the Soviet Union. To this end, Sweden maintained a sizable navy, and was concerned with interdicting any foreign forces that violated Swedish territorial waters in the Baltic Sea. From 1974 to 1981, a series of incidents occurred in which the Swedish Navy claimed to have detected foreign submarines near or inside Swedish territorial waters. Most notably, in 1981 an incident occurred in which the became grounded off the coast of

Karlskrona Naval Base The Karlskrona naval base () is the largest naval base of the Swedish Navy. Located in Blekinge in southern Sweden, the base has close ties with the city of Karlskrona. It has an exceptionally well-sheltered location: arcs of islands provide a ...

; further inflaming tensions was the fact that the grounded submarine was well within Swedish territorial waters and possibly armed with nuclear weapons. The incident in 1981 led to heightened Swedish fears of Soviet infiltration of Swedish waters, a concern which was reflected in the Swedish navy's actions during the Hårsfjärden incident.

The incident

In 1982, the Swedish government planned to conduct an anti-submarine warfare exercise to test the nation's ability to detect and destroy foreign submarines. This exercise was planned for September 1982, and coincided with

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

military exercises A military exercise, training exercise, maneuver (manoeuvre), or war game is the employment of military resources in training for military operations. Military exercises are conducted to explore the effects of warfare or test tactics and strat ...

in the Baltic. The complete purpose of the Swedish exercise (termed Operation NOTVARP) remains a matter of debate; some sources speculate the operation was a standard military exercise modified to respond to a false alarm, while others posit the operation was either a pre-planned attempt to entrap a foreign submarine (using unknowing American warships calling in Stockholm as bait) or an opportunistic attempt to engage a trespassing submarine. During this same time, the Swedish parliament (having been reshuffled after a series of elections) was in a state of flux, effectively leaving the nation without a government from late September to early October. On the morning of 30 September, Swedish naval units detected an unknown foreign submarine entering

Hårsfjärden The Hårsfjärden, or Horsfjärden (), is a fjard off the Baltic Sea near Stockholm, Sweden. About long, it has surface area of . It is the location of three Swedish naval bases: Märsgarn, Muskö, and Berga Berga () is the capital of the ''C ...

Bay, where the Swedish Navy had established a

hydrophone A hydrophone () is a microphone designed for underwater use, for recording or listening to underwater sound. Most hydrophones contains a piezoelectric transducer that generates an electric potential when subjected to a pressure change, such as a ...

network and placed

naval mine A naval mine is a self-contained explosive weapon placed in water to damage or destroy surface ships or submarines. Similar to anti-personnel mine, anti-personnel and other land mines, and unlike purpose launched naval depth charges, they are ...

s to interdict an intruding submarine. The detection of the submarine caused the Swedish Navy to scramble its forces, though disagreements on how the navy should proceed with the submarine situation delayed an armed response to the intrusion. Once a decision was reached, Swedish forces began to hunt for the submarine; between 1 October and 14 October, numerous sonar contacts and purported sightings (including the detection of an oil slick) prompted the Swedish Navy to drop

depth charge A depth charge is an anti-submarine warfare (ASW) weapon designed to destroy submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited ...

s, deploy

minesweeper A minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping. History The earliest known usage of ...

s, order increased naval patrols, and attempt to seal off Hårsfjärden Bay with a series of metal barriers. The last report of the suspect submarine dates to 14 October, though the search would continue in some capacity until 1 November.Sadurska, Roma (1984). ''Foreign Submarines in Swedish Waters: The Erosion of an International Norm.'' Yale Journal of International Law. Yale University. Issue 1, Volume 10, Article 5. URL: http://digitalcommons.law.yale.edu/cgi/viewcontent.cgi?article=1314&context=yjil During the search, the navy found what may have been

caterpillar tracks Continuous track or tracked treads are a system of vehicle propulsion used in tracked vehicles, running on a continuous band of treads or track plates driven by two or more wheels. The large surface area of the tracks distributes the we ...

on the seabed, indicating the incident may have involved

midget submarine A midget submarine is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to six or nine, with little or no on-board living accommodation. They normally work with mother ships, from which they are launched an ...

s or undersea vehicles.Gustafsson, Bengt. ''The Swedish Submarine Issue''. NR 3 juli/oktober 2010. URL: https://www.kkrva.se/wp-content/uploads/Artiklar/103/kkrvaht_3_2010_6.pdf

Identity of the intruder

At the time of the incident, most sources indicated that the intruding submarine was from the Soviet Union—this general consensus has continued to the present day. Most sources cite the previous Soviet infiltrations, the length of the search, the acoustic profile of the intruder (garnered from active and passive sonar pings detected during the incident) matching a diesel-powered submarine, and the former Soviet Navy's (and later Russian Navy's) culture of secrecy and inconsistent record keeping at the time of the incident as evidence of the intruder being a Soviet submarine. Other sources have speculated the submarine was present in Sweden during late September in order to track several American warships that were docked in Stockholm and to test the resolve of the then newly-elected Swedish parliament. In the years after the incident, other sources have theorized that the submarine was from a NATO nation (likely the United States or Great Britain). Swedish professor

Ola Tunander Göran Ola Tunander (born in Stockholm, Sweden in 1948) is a research professor emeritus at the Peace Research Institute Oslo (PRIO, Norway). He worked as a researcher at PRIO in the period 1987-2016. He is the son of Museum Director Ingemar Tuna ...

posited that a NATO submarine (either serving as an escort for American ships docked in Stockholm or attempting to test the effectiveness of Swedish anti-submarine defenses) had inadvertently found itself trapped in a Swedish defensive system and been attacked; Tunander cited descriptions of the submarine's periscope, the secretive nature of Swedish government documentation of the event, and reports of green water (British and American submarines used green-colored chemical dyes for emergency signaling) being seen near one of the submarine's suspected locations. Other sources speculate that the incident was sparked not by a submarine, but by a series of Swedish surface ships that had inadvertently triggered the navy's anti-submarine measures.

Aftermath

In the aftermath of the Hårsfjärden incident, the Swedish Parliament conducted an investigation into the event and the Swedish Navy's state of preparedness. The incident led to increased Swedish military awareness, and the event has been cited as an example of how the emergency policies of nations can be tested during unexpected international incidents.BYNANDER F. ''The 1982 Swedish Hårsfjärden Submarine Incident: A Decision-Making Analysis''. Cooperation and Conflict. 1998;33 (4). pp. 367-407

References