In the past few years, Russian submarine activities have become a focal point for U.S. and NATO planners, part of the larger discourse on Russia’s revanchist role in the wake of its illegal annexation of Crimea. Several military leaders have observed that Russian activities in the undersea domain have reached the highest levels seen in 20 years, and this heightened pace of operations has set off alarm bells from the United Kingdom to Finland and spurred comparisons to the Cold War.1

Such comparisons have led to a focus on the Greenland-Iceland-United Kingdom (GIUK) Gap, a vital antisubmarine warfare (ASW) chokepoint during the Cold War and a major component of NATO force and operational planning.2 Unfortunately, the focus on the GIUK Gap showcases the danger of planning for the last war. While the challenges feel familiar, rapidly expanding long-range strike capabilities mean Russian submarines no longer have to transit the gap to have a dramatic impact on the European military balance. Rather, they can operate from the relative safety of bastions in the Norwegian and Barents seas and strike targets across Northern and Central Europe. A response centered on the GIUK Gap risks misprioritizing future investments.

Russian Naval Power: 1950–Today

The fundamental mission of the Russian/Soviet Navy has not changed since the 1960s. It is a force designed to prevent NATO from using the sea as a maneuver space. The Soviet Navy was the quintessential sea-denial force. It relied heavily on submarines and surface vessels with considerable antiship armaments, supplemented with long-range naval aviation assets armed with potent antiship missiles to prevent adversary “aeromarine” attacks on Russian territory.3

While the Soviet Navy focused on keeping NATO out, NATO was concerned about Soviet nuclear capabilities. In the early stages of the Cold War, Soviet ballistic missile submarines (SSBNs) needed to transit the GIUK Gap to reach targets in the continental United States. The first- and second-generation submarine-launched ballistic missiles (SLBMs) did not have the range to reach targets in the United States from secure bastions in the Arctic.4

Under the auspices of Project Hartwell and Project Nobska, the U.S. Navy made revolutionary investments in ASW capabilities and operations to address the threat.5 This included creation of the Sound Surveillance System (SOSUS), a network of seafloor hydrophones to monitor and track Soviet submarines. All of the then–relatively noisy Soviet submarines that passed through the natural chokepoint of the GIUK Gap would be detected by SOSUS and subsequently tracked. Allied ASW, including SOSUS, provided NATO forces a significant advantage in the Cold War undersea competition.6

The nature of Cold War ASW changed in the mid-1970s with the launch of the third generation of Soviet SSBNs, the Project 667B Delta class. These boats carried the long-range R-29 SLBM capable of hitting targets in the United States from the far North Atlantic, Barents Sea, and Arctic Sea. The U.S. Navy no longer could rely on Soviet SSBNs coming to it.7 It would need to operate forward, near Soviet territory, to conduct counterforce operations.

The requirement to operate forward and penetrate Soviet SSBN bastions was further stressed by dramatic improvements in acoustic performance made by the Soviet Union in the early 1980s. The final incarnation of the Delta-class design, the Project 677BDRM Delta IV, sent shockwaves through the U.S. naval establishment when it launched. Its acoustic performance was a giant leap forward, challenging U.S. capabilities for submarine detection and tracking.8

In response, U.S. submarine operations moved forward into the Barents Sea and Arctic Sea. The last phase of underwater competition between the United States and the Soviet Union was characterized by forward attack submarine (SSN) operations and near acoustic parity. This informed the design choices for the U.S. Seawolf-class SSN, including an increased weapons load, extensive sonar arrays, increased diving performance, and new propulsion technology.9 Together, these systems enabled the Seawolfs to operate persistently in contested areas while maintaining the high search rate needed to hunt quiet Soviet submarines.

While the GIUK Gap no longer was important in the context of the nuclear counterforce mission, the Soviet Navy maintained a core of SSNs (including the Project 945 Sierra, Project 971 Akula, and Project 671 Victor classes) equipped to attack NATO naval forces in the wider Atlantic. In addition, it deployed the Project 949 Oscar- and Project 949A Oscar II–class guided-missile submarines (SSGNs) specifically designed to kill U.S. carrier battle groups. The clear desire of the Soviet Navy to deny NATO use of the seas meant the GIUK Gap, and the associated barrier defense concept, retained a degree of importance even after the Soviet SSBNs retreated to bastions in the far north.

The last generation of Soviet SSNs and SSGNs from the 1980s were just as quiet as the Delta IVs. The final batch of Akulas built before the dissolution of the Soviet Union were quieter still. SOSUS and the Integrated Undersea Surveillance System no longer were the silver bullets they had been during the halcyon days of the 1960s. The United States and NATO responded with both technical and operational solutions. On the technical front, the United States invested in new deployable acoustic surveillance systems, including the Surveillance Towed Array Sonar System (SURTASS) and its controversial low-frequency active component.10 Concurrently, technical solutions were paired with increased cooperation between surface and aerial assets to track Soviet submarines.

After the Cold War, the United States and NATO largely abandoned their ASW capabilities, but the reemergence of Russian antagonism has refocused them on the submarine threat. They have reached for the familiar: focusing on the GIUK Gap, deploying U.S. ASW aircraft to Keflavik in Iceland, and holding major NATO ASW exercises off the Norwegian coast. This is the wrong path to confronting the modern Russian undersea challenge.

The Advent of Russian Long-Range Strike

The primary mission for Russian attack and guided-missile submarines is to prevent the reinforcement of the European theater from the United States by sea. Today’s Russian platforms may resemble those of the Cold War, but their weapon systems have improved dramatically. Russia does not need to hunt sealift vessels in the open ocean to halt reinforcement of NATO across the Atlantic. Its long-range land-attack cruise missiles can strike the vital North Sea port infrastructure in Belgium, the Netherlands, and Germany from launch platforms in the Norwegian and Barents seas. The revolution in Russian naval long-range strike capabilities has dramatically decreased the relevance of the GIUK Gap.

The long-range strike payload of a single Project 885 Yasen-class SSN likely would cripple Bremerhaven, the primary U.S. surface port of debarkation in Europe. This is the single most important node for moving heavy equipment to the European theater. Bremerhaven would be particularly easy to disable, as the vehicle port is accessed through two locks. In addition, the rail line to the port goes over two rail bridges. Destroying these targets would render the port largely inoperable for U.S. needs.

Today, Russia does not need to hunt sealift vessels in the open ocean to halt U.S. reinforcement of NATO. Its long-range land-attack cruise missiles can strike vital North Sea infrastructure such as the port of Bremerhaven—the primary U.S. surface port of debarkation in Europe—from the Norwegian and Barents seas. U.S. Army (Micah VanDyke)

Alternative ports such as Rotterdam and Antwerp are more resilient because of their larger size, but they have some of the same weaknesses as Bremerhaven. For example, a portion of Antwerp is accessed through a lock system that if rendered inoperable would bring port operations to a halt. In addition, onward rail movement relies heavily on a series of bridges that span the Dutch canal system. Brittle points in the European logistics system were thought to be secure during the Cold War; this no longer is the case.

The Russian Navy is in the middle of a generational change in its power projection and long-range strike capabilities, as demonstrated by its support of combat operations in Syria.11 Russian thinkers during the 1980s understood that precise long-range strike capabilities could reach targets previously believed to be rear area sanctuaries. Writing about a “military technical revolution,” they foresaw how increases in range and precision would render previous classes of weapons largely impotent. The Gulf War confirmed the Russian views.12

Precise deep strike against rear logistics areas was the exact problem NATO imposed on Soviet forces at the end of the Cold War. This is the world NATO planners now face. While Russian analysts and policymakers, including President Vladimir Putin, have complained loudly about the destabilizing effects of long-range strike weapons, they have been diligently developing their own versions.13 The now-infamous 3M14 Kalibr naval land-attack cruise missile, with a purported range of up to 1,500 miles, gives the Russian Navy a long-range strike capability it has never before possessed.14

Land-attack weapons now are included on nearly all new-design vessels for the Russian Navy. The Project 636 Improved Kilo-class submarines Kolpino and Veliky Novgorod demonstrated their strike capabilities, launching Kalibr missiles at targets in Syria. Sputnik

The importance of land-attack weapons to Russian naval power is evident in their inclusion on nearly every new-design vessel the Russian Navy has commissioned in the past five years. The Yasen-class SSNs often are termed SSGNs because of their significant missile payload, believed to be up to 40 Kalibrs.15 Russia also has prominently displayed the long-range strike capabilities of its new Project 636 Kilo-class submarines and is planning to modernize the Oscar II class to carry up to 96 Kalibrs.16 This last step would give the Russian Navy a capability akin to that of the U.S. Ohio-class SSGN.

The New Future for NATO Maritime Forces

Russia’s new strike capabilities give its navy and, in particular, its submarine fleet a tremendous ability to influence the European military balance. The GIUK Gap will not provide a geographic crutch to help mitigate the threat, as long-range weapons allow Russian submarines to operate from the relative security of the Norwegian and Barents seas.17 For example, a submarine-launched cruise missile (SLCM) with a range of 1,000 miles would give the Russian Navy a potential patrol area of 100,000 square miles from which it could strike Bremerhaven while remaining reasonably secure. An SLCM with a notional range of 1,250 miles would increase the likely patrol area to more than 220,000 square miles, including waters north and west of the island of Jan Mayen, 500-plus miles from the nearest NATO ASW base. A longer range would allow Russian boats in the White Sea to strike targets in northeast Europe, most notably the Aegis Ashore site in Poland. In addition, likely North Atlantic patrol zones are only one to three days’ sail from Russian bases on the Kola Peninsula, decreasing their exposure to NATO ASW assets.

This new reality cannot be addressed by focusing on the GIUK Gap. To respond adequately, the United States and NATO must move beyond the outdated barrier-defense concept and fully embrace open-ocean ASW, with far greater emphasis on operating in contested waters well north of the Arctic Circle. Instead of static ASW barriers, the United States and NATO must shift to a model of mobile ASW nets that can be rapidly constituted and focused on likely areas of operation.

This will require developing a new generation of ASW capabilities. Chief among potential systems are large unmanned underwater vehicles (UUVs) with considerable on-station time to provide initial cueing for other ASW assets. In addition, the Navy will need a new family of disposable acoustic ASW payloads. A major element would be small, disposable UUVs and unmanned surface vessels (USVs) deployed by ships, aircraft, submarines, or large UUVs that could quickly be seeded into an area and provide persistent ASW coverage for upward of a week.

These new capabilities will be effective only if they are paired with a new networking concept that knits together aerial, surface, and subsurface assets to understand the undersea battlespace. This is a daunting technical challenge, likely achievable only if subsurface platforms have considerable onboard processing and analytic capacity and are supported by persistent communication nodes.

While these technical solutions, and the new operational concepts they enable, will help detect and track Russia’s submarine fleet, they must be paired with SSNs with the speed, stealth, and sensors to hunt the latest generation of Russian submarines. By unshackling themselves from past modes of thinking and forging new and existing capabilities together, the United States and its NATO allies will be able to meet the evolving challenge posed by the Russian submarine fleet.