GIUK gap

The GIUK gap in the NorthAtlantic(showing international boundaries as of 1983)

TheGIUK gap(sometimes written G-I-UK) is an area in the northern Atlantic Ocean that forms anavalchoke point.Its name is anacronymforGreenland,Iceland,and theUnited Kingdom,the gap being the two stretches of open ocean among these three landmasses. It separates theNorwegian Seaand theNorth Seafrom the openAtlantic Ocean.The term is typically used in relation to military topics. The area has for some nations been considered strategically important since the beginning of the 20th century.

The strategic significance of the GIUK Gap to the Kingdom of Denmark

ComprisingGreenland,theFaroe IslandsandDenmark,theKingdom of Denmarkis an Arctic state alongside seven other countries whose territories cover theArcticregion.All matters of foreign policy for bothGreenlandand theFaroe Islandsfall within the jurisdiction of the Danish government.

The Danish government has historically used its jurisdiction over foreign policy in bothGreenlandand theFaroe Islandsto assist in securing the GIUK gap and the widerArcticfor its allies. In doing so, Denmark has arguably acquired a sense of goodwill from particularly theUS governmentandNATO.The Danish government views theArcticas a central component of its foreign security policy and will continue to expand its spending, surveillance and military presence in the region.

Despite the relatively small-sized population of theKingdom of Denmark,roughly 6 million, the Danish government's close ties toGreenlandand theFaroe Islandslegitimises it as an inherently importantArcticactor on matters of geopolitical security and great-power tensions. Danish assertion of sovereignty in the GIUK gap and the widerArcticis already a key concern to theRealmand is expected to be an increasingly important component ofDenmark'sfuture responsibilities inNATO.

The GIUK gap is also a key supply line between theUSand its European allies. With war on-going inUkraine,NATOand theUSare showing renewed interest in the GIUK gap,positioningDenmarkto be a key player in matters of broader European security and increasing the gap's strategic importance to theDanish Realm.

Securing air and sea visibility in the GIUK Gap

Until 2007, theFaroe Islandswere home to an air surveillance radar station, providing vital radar coverage during theCold War.In light of broader geopolitical changes, such as thewar in Ukraine,c.2022, the station was undergoing preparations to be reopened, closing an important surveillance gap in the GIUK gap.

Maintaining thorough surveillance of the GIUK gap is crucial in order to ensure thatsea lines of communication (SLOCs)and supply lines are uninterrupted betweenNATO'sEuropean members and theUnited States.Military bases, space bases, surveillance drones and radar installations in bothGreenlandand theFaroe Islandscan help ensure proper visibility in the region, and assist inanti-submarine warfare (ASW)in case of actual conflict.In 2021, Denmark unveiled a $250m investment in surveillance capabilities inGreenlandand theFaroe Islands.

Responding to requests fromNATOforDenmarkto play its part in securingArctic waters,Denmarkis taking further steps to equip its ASW-frigates with sonar equipment, making them better equipped to detect and tracksubmarinesin theArctic Ocean,and particularly in the GIUK gap. In addition, theDanish governmentis equipping its Seahawk helicopters with sonar equipment and torpedoes. The upgrades have yet to be delivered, however, with delivery projections estimating 2024 at the earliest.

Threats to critical seabed infrastructure

During theCold War,Russiarelied on the ability of its nuclear submarines to pass through the GIUK gap in order to ensure maximum military capability. The introduction of long-range precision strike weapons, however, have reduced the significance of the GIUK gap in relation to intercontinental attacks and made it possible forRussiato target North American sites from safer waters, such as theNorwegian Sea.Still, the GIUK gap remains the obvious access point for Russian military operations in the wider NorthAtlantic Oceansince most ofRussia'shighest quality naval capabilities are deployed in theNorthern fleet,making the GIUK gap a significant transit route.

ForNATOallies, the GIUK gap is vital in terms of barrier defense forsea lines of communicationprotection.SLOCsare vulnerable in theNorth Atlanticboth in the gap and beyond, and theUSandNATOrely on theKingdom of Denmarkto assist in protecting this critical infrastructure, including the vast number of seabed data cables.

The Russian fleet has in recent years strategically upgraded its capabilities for covert subsea operations related to the targeting of seabed infrastructureand reports of Russian "mapping" of critical seabed infrastructure in theNorth Seaand the seabed aroundDenmarkare increasing.NATO intelligence and security officials confirm these reports, warning that Russia has both the intent and necessary capabilities to target critical seabed installations if they so choose.While such infrastructure has always been associated with some risk, the dependency ofDenmarkand its allies on them are only increasing and is therefore posing a major threat in times of tension short of actual conflict.

The September2022 Nord Stream pipeline sabotagein theBaltic Seaproves the fragility of seabed infrastructure and underscore the need for theDanish governmentto maintain a strong Arctic responsibility in the GIUK gap.

Importance for the Royal Navy of the UK

See also:Armed forces of Scotland § GUIK gap

The GIUK gap is particularly important to theUK's Royal Navy,as any attempt by northern European forces to break into the open Atlantic would have to be made either through the heavily defendedEnglish Channel,one of the world's busiest seaways,or through one of the exits on either side of Iceland. As the British also control the strategic port ofGibraltarat the entrance to theMediterranean,this means Spain, France, and Portugal are the only Continental European countries that possess direct access to the Atlantic Ocean that cannot easily be blocked at a choke point by the Royal Navy.

History

Since the beginning of the 20th century, the exploitation of the GIUK gap by northern forces and measures to patrol and secure the gap by opposing forces have played an important role in naval and in overall military planning.

World War II

From the start ofWorld War IIin 1939, German ships used the gap to break out from their bases in northern Germany (and fromoccupied Norwayafter April 1940) with a view to attacking Allied shippingconvoys,but Allied blocking efforts in theNorth Seaand in the GIUK gap impeded such break-outs. British forcesoccupied the Faroe Islandsin April 1940, andIcelandin May 1940; the United States took over effective control of Greenland in 1940. But the GermanKriegsmarineprofited greatly from thefall of Francein June 1940, after which Germansubmarinescould operate from bases on the French coast.

The origin of the term "gap" dates to this period, when there was a gap in air coverage known as theMid-Atlantic gapor the "Greenland air gap". This gap was an area that land-based aircraft could not reach and where, as a result, they could not carry out theiranti-submarineduties.

Cold War

The GIUK gap again became the focus of naval planning in the 1950s, as it represented the only available outlet into the Atlantic Ocean for Soviet submarines operating from their bases on theKola Peninsula.NATOworried that if theCold War"turned hot", naval convoys reinforcing Europe from the U.S. would suffer unacceptable losses if Soviet submarines could operate in the North Atlantic. The United States and Britain based much of their post-war naval strategy on blocking the gap, installing a chain of underwater listening posts right across it during the 1950s – an example of aSOSUS"sound surveillance system". This deployment of sonar surveillance in the gap, and elsewhere, hampered the SovietNorthern Fleet's ability to deploy its submarines without detection.

The Royal Navy's primary mission during the Cold War, excluding its nuclear deterrent role, involvedanti-submarine warfare(ASW). The development of theInvincible-classASWaircraft carriersstemmed from thisdoctrine:their primary mission involved anti-submarine warfare usingSea Kinghelicopters. TheType 23 frigateoriginated as a pure ASW platform; its mission expanded following theFalklands Warof 1982.

The largest Russian submarine drills through the GIUK gap were operations Aport and Atrina, in 1985 and 1987, respectively, when the Soviets deployed several SSNs near the U.S. coast before the1985 Gorbachev–Reagan meeting.

The Soviets planned to use the GIUK gap to intercept anyNATOships, especially aircraft carriers, heading towards the Soviet Union. Ships and submarines as well asTupolev Tu-142maritime-surveillance aircraft aimed to track any threatening ships.

The advent of longer-ranged Sovietsubmarine-launched ballistic missiles(SLBMs) allowed the Soviet Navy to deploy theirballistic missile submarine(SSBNs) within protected bastions in theBarents Seaand reduced their need to transit the GIUK gap. The much reduced, post-Cold War Russian Navy has even less need to transit the GIUK gap.

Crossing the GIUK gap was a major strategic move for Ocean Venture in 1992, in which 84 NATO ships, including 4 US aircraft carriers, departed from their usual August exercise pattern, deployed a decoy south toward the mid-Atlantic, and then entered waters in a move that had historically been associated with a risk of destabilizingdétente.

Post-Cold War

In late October 2019, a week before Commander of theNorthern FleetAleksandr Moiseyevand Russian Foreign MinisterSergey Lavrovmet their Norwegian counterparts inKirkenes,Norway, ten submarines of Russia's Northern Fleet, among them two diesel-electric and eight non-strategic nuclear, left their homebases in theKola Peninsulato participate in submarine drills that were the largest, on the Russian side, since Cold War operationsAport and Atrina. The main task of the submarines was reportedly testing Russian ability to breach the GIUK gap undetected and sail into the Atlantic Ocean. The drills were expected to last up to two months.

Bird migration

The GIUK gap is also a route formigratory birdssuch as thenorthern wheatearto cross the Atlantic to reach Greenland and eastern Canada.

In popular culture

• The 1960 British war filmSink the Bismarck!discusses the strategic importance of the GIUK gap during World War II naval operations in the Atlantic theatre, and depicts theBattle of the Denmark Straitbetween British and German forces. It is based on the novelThe Last Nine Days of the BismarckbyC. S. Forester.
• The GIUK line is mentioned in the filmThe Bedford Incident.
• InTom Clancy's first novel,The Hunt for Red October,the line was used to detect Soviet submarines entering the North Atlantic in pursuit of the rogueTyphoon-class submarineRed October,whose officers were defecting to the United States with clandestine stealth technology. The event causes significant political and military tension between the United States and theSoviet Union.Thefilm adaptationalso references the gap, withNational Security AdvisorJeffrey Pelt (played byRichard Jordan) saying to the Soviet ambassador "Your aircraft have dropped enoughsonar buoysso that a man could walk from Greenland to Iceland to Scotland without getting his feet wet. "
• In Clancy's second novel,Red Storm Rising,the line is featured more prominently after a war breaks out betweenNATOand theWarsaw Pact.TheSoviet Unionlaunches a surprise attack on the NATO airbaseNAS Keflavikand invades Iceland. This causes the line to be destroyed, creating a gap in NATO's surveillance and allowing theSoviet Navyto enter the North Atlantic. The subsequent Soviet submarine attacks and air raids cause serious damage toMerchant Marineships and naval vessels inAtlantic convoys,hindering NATO's war effort during the defense against the less-successful Soviet invasion of West Germany.
• Early editions of theHarpoonnaval warfare simulation were based around defending the GIUK Gap. Tom Clancy used the simulation to test the naval battles forRed Storm Rising.
• The location of Iceland in the gap made it a participant in the Cold War and a target for a nuclear strike, especially through the introduction of the aforementioned Keflavik atomic bomber NATO base.Halldór Laxnessdramatized the tension of these geopolitics from the perspective of an Icelandic maid in the novelThe Atom Station.

See also

• Battle of the Denmark Strait– Naval battle during the Second World War
• Broad Fourteens– Area of the southern North Sea
• Communication with submarines– Submarine communication
• Long Forties– Zone of North Sea
• Mid-Atlantic gap– Area outside airplane range in World War II
• SOSUS– Cold War-era passive, fixed array undersea surveillance system
• Western Approaches– Area of the Atlantic ocean lying immediately to the west of Ireland and parts of Great Britain
• Luzon Strait– Strait between Luzon and Taiwan
• Strait of Malacca– Strait between the Malay Peninsula and the Indonesian island of Sumatra
• Strait of Gibraltar– Strait connecting the Atlantic to the Mediterranean
• Turkish Straits– Two waterways in TurkeyPages displaying short descriptions of redirect targets

Land:

• Focșani Gate– Militarily and strategically important area in Romania and NATO
• Fulda Gap– Cold War strategically important area
• Suwałki Gap– Lithuania–Poland border area