The maritime domain is increasingly a priority for NATO as the alliance seeks to bolster its defense and deterrence posture in Europe’s north and east. Much work remains to be done in terms of NATO’s maritime posture and the maritime capabilities and capacities of its members. The maritime domain presents a unique challenge for NATO’s Baltic members, as they are frontline states in the new contest between NATO and a revanchist Russia. This issue brief lays out the particular challenges for the Baltic States in the maritime domain in the Baltic Sea region, and how Estonia, Latvia, and Lithuanian can build more effective maritime defense in concert with NATO and the United States.


Northern Europe, and in particular the Baltic Sea region, has become a critical friction zone between NATO and an assertive Russia that seeks to alter European security in its favor by fracturing NATO and dislodging the United States as the ultimate guarantor of peace and security in the region. Since 2014, the United States, NATO, and the nations of Europe have made considerable progress toward bolstering deterrence and defense in the region by, among other things, allocating additional resources to national defense, reorienting the armed forces toward territorial defense tasks, stepping up national and NATO exercises, and by deploying an allied forward presence through the enhanced forward presence (eFP) groups in Estonia, Latvia, Lithuania, and Poland.

The NATO and national responses to Russia’s continued assertiveness to date have, however, emphasized the ground domain in terms of the focus on capabilities, exercises, and structures. Only more recently have NATO and its members turned their attention to the maritime and air domains as important components of an effective deterrence and defense construct for northern Europe. And in this context, most of the interest has focused on the larger Baltic Sea nations, such as Germany and Poland, and those NATO members from outside of the region that could bring significant maritime capabilities into the Baltic Sea during a crisis in the region, such as the United States, the United Kingdom (UK), and France. But in order to build a comprehensive approach to deterrence and defense in northern Europe, the maritime threats and challenges to the Baltic states themselves must be carefully considered along with their maritime interests, and the capabilities and functions they can, or could, bring both at sea and ashore.

This report provides a specific look at the three Baltic states and the relevance of the maritime domain to their defense, both nationally and as members of NATO, and what future capabilities, functions, and forms of cooperation the three countries should consider to further enhance defense and deterrence in the maritime domain of the Baltic Sea region.

Current state of Baltic Sea regional security

The Maritime Environment and the importance of the Baltic Sea

The Baltic Sea is a busy maritime domain that carries a significant volume of trade among the Baltic Sea nations, and between the region, the rest of Europe, and the broader world; close to 15 percent of the world’s maritime cargo traffic is related to the Baltic Sea region. The Baltic Sea is also an increasingly important route for energy exports and imports and includes a substantial commercial fishing fleet. The Baltic Sea region is of vital importance to Russia as well. It provides an important outlet for Russian exports, including 50 percent of Russia’s cargo traffic, as well as energy exports via pipelines and shipping. The Baltic Sea also provides maritime connectivity between the Kaliningrad enclave and the rest of Russia.

In terms of its operating environment, the Baltic Sea is challenging for maritime forces. Much of it is shallow in depth, and access to the region is controlled by narrow inlets such as the Danish Straits. The Baltic Sea is busy with commercial shipping, especially toward the south, which creates clutter and constrains the ability of naval forces to maneuver during peacetime. The Baltic Sea is also relatively narrow (its average width is only 120 miles), meaning that modern ground-based systems, such as air defense and anti-ship missile batteries can range over much of the maritime domain in the region. This threat is especially acute in the southeastern corner of the Baltic Sea, where Russia is developing a robust anti-access/area-denial (A2/AD) network in its Kaliningrad enclave.

Russia’s Baltic Sea fleet

Russian naval power is more constrained in the Baltic Sea today in comparison to the Cold War. Russia lost its maritime infrastructure and bases in the Baltic states when Estonia, Latvia, and Lithuania regained their independence, and now only maintains naval forces and supporting infrastructure in Kaliningrad and in the vicinity of Saint Petersburg. Russia’s Baltic Sea fleet has also received comparatively less attention than the Northern and Black Sea fleets in Russian military modernization efforts. Today, the Baltic Sea fleet consists of some fifty ships, including two destroyers, six frigates, six corvettes, two submarines, a collection of mine hunters, and assorted smaller surface ships. Many of these are of Cold War vintage, and have not been modernized since then. Although the Baltic Sea fleet is significantly more active today in comparison to the last decade, concerns remain about readiness levels and crew proficiency.

Nevertheless, while the Baltic Sea fleet is far from its strength during the Cold War, it could still play a potent sea-denial role as part of a Russian anti-access/areadenial campaign against NATO and the United States during a crisis in the region, especially using smaller naval platforms with long-range, anti-ship, and landattack missiles, a current priority in Russian naval modernization and a capability already demonstrated in the Mediterranean against targets ashore in Syria.1Reuters Staff, “Russian frigate fires cruise missiles at Islamic State
targets near Syria’s Deir al-Zor,” Reuters, September 5, 2017
In addition, naval power is inherently mobile over strategic distances, and Russia has displayed a pattern of moving important naval assets between theaters of operation as needs change. Indeed, in late 2016 two new corvettes from Russia’s Black Sea fleet, capable of carrying long-range kalibr cruise missiles, entered the Baltic Sea as an augmentation to the Baltic Sea fleet. This adds further to Russia’s high-end maritime capabilities in the region.2Damien Sharkov, “Russia’s Baltic Fleet to Receive New Missile
Corvette and Bomber,” Newsweek, May 17, 2017, http://www.

NATO in the Baltic Sea

Over the last three years, the Baltic Sea region has seen an increase in maritime exercises both in scope and in number. The annual BALTOPS exercise, driven by the US Sixth Fleet, has expanded considerably and is increasingly focused on high-end maritime warfighting in the Baltic Sea as well as missions such as anti-submarine warfare, air defense, and amphibious landings. National and other multinational exercises in the region, such as Northern Coasts, have also increased since 2014. The navies of the Baltic states (including both ships and staff members) are frequent participants in these exercises.

In combination, the navies of the Baltic Sea region bring a considerable set of capabilities that would be relevant to a crisis in the region. For example, Germany and Sweden (the latter a close NATO partner nation) provide high-end, sub-surface warfare capabilities and expertise with their submarine forces, even though these forces are numerically smaller than levels maintained during the Cold War. Current naval investment plans for the navies of the region also point to a strong focus on high-end naval warfighting, including anti-submarine warfare (ASW), air defense, sub-surface warfare, and electronic warfare.3See Magnus Nordenman and Franklin D. Kramer, “A Maritime
Framework for the Baltic Sea Region,” Atlantic Council, April 6,

These developments in maritime capabilities and exercises in the Baltic Sea are a reflection of more attention to the maritime domain within NATO more broadly. NATO has also increased the size and complexity of naval exercises elsewhere, such as the North Atlantic and the Mediterranean, and movement in the Alliance is expected on command structure and strategy related to operations in the maritime domain.

The maritime domain and challenges to Baltic security

Due to location, geography, and available resources, the maritime domain presents unique challenges for Estonia, Latvia, and Lithuania. Fundamentally for the Baltic states, it is not a matter of operating across the Baltic Sea (as it is for most NATO members) but to keep its approaches and ports open for seaborne NATO reinforcements. In a high-end conflict scenario in northern Europe, the maritime domain would play an important supporting role. A Russian offensive would likely include all domains of warfare (ground, air, sea, and cyber) and, in the case of the maritime domain, could include efforts to deny the use of any Baltic port as a seaport of debarkation for reinforcements, or to strike at what could be perceived as a vulnerable flank. Indeed, it would be useful to draw on lessons learned from the Russian annexation of Crimea, which was primarily a ground operation, but did include maritime elements to reinforce the initial Russian deployment and to frustrate the initial Ukrainian military response to the crisis. Maritime efforts aimed at the Baltic states during a crisis could include limited amphibious landings, mining of maritime approaches, sabotage by maritime special operations forces, and strikes from the sea using long-range missile systems.

The Baltic states must also consider hybrid challenges in the maritime domain that would leave them vulnerable in scenarios that do not reach the threshold for NATO’s Article 5. For example, the Baltic states rely on seabed infrastructure, such as communications and electricity cables in the Baltic Sea for connectivity to the rest of the Baltic Sea region and beyond, which could be disrupted during a crisis with Russia. Latvia and Lithuania are particularly vulnerable in such a scenario, given the limited number of nodes connecting them to the undersea cables. Indeed, Russia has taken a growing interest in operating close to undersea infrastructure for surveillance and training purposes, and the construction of an electricity linkage between Sweden and Lithuania served as the pretext for aggressive Russian behavior toward the ships laying cables in the Baltic Sea in 2015.4For more on hybrid maritime threats in the Baltic Sea region see
Martin Murphy, Frank Hoffman, and Gary Schaub, Hybrid Maritime
Warfare and the Baltic Sea Region, Centre for Military Studies,
University of Copenhagen, October 25, 2016, http://cms.polsci.

Finally, the Baltic states must consider peacetime naval challenges from Russia, which are to some degree part of the new normal in the Baltic Sea region, but must nevertheless be heeded and managed. These include the persistent surveillance conducted by Russia in the air and at sea aimed at territory, units, infrastructure, training, and exercises; close encounters between aircraft and ships from Russia and NATO members; and potential incursions into the sea and airspace of the Baltic states. These challenges are not necessarily part of a crisis escalation scenario, but must be monitored, responded to, and better understood not only by the Baltic states and the other Baltic Sea nations, but across the Alliance in order to build familiarity with the maritime dynamics of the region among decision makers. Indeed, most of the close and potentially dangerous encounters between Russia and NATO in the Baltic Sea region do not involve warships or shipping from the Baltic states, but instead are focused on deployed ships from other NATO nations, in particular the United States.

The navies of Estonia, Latvia, and Lithuania are small and primarily focused on mine hunting, an understandable post-Cold War maritime capabilities evolution. After the collapse of the Soviet Union, the newly independent Baltic states found their coasts and waters littered with World War II era mines and unexploded ordnance that threatened commercial shipping and fisheries. The mine-hunting mission with Mine Countermeasure ships was also seen as a real and practical contribution to NATO’s increasing out-of-area focus with its Standing NATO Mine Countermeasures Groups (SNMCG). Over the last two decades, the Baltic states have built up considerable mine-hunting expertise and are viewed as leaders within NATO in this field.

In combination, the Baltic states have some twelve mine-hunting vessels at their disposal, along with an assortment of patrol vessels with limited surface warfare capabilities. Naval modernization efforts among the Baltic states have included a limited set of anti-submarine warfare sensors, coastal surveillance networks, and further enhancements of the preexisting mine countermeasure (MCM) capabilities. Moving forward, the naval modernization efforts of the Baltic states are expected to remain relatively modest. Estonia, Latvia, and Lithuania have all reached NATO’s agreed commitment of 2 percent of gross domestic product (GDP) for defense and have ambitious modernization and readiness plans in place. However, given the small size of the Baltic economies and the many competing demands (including, but not limited to, anti-armor capabilities, soldier protection, mobility, and air defense), the resources available for maritime capabilities will remain modest.

The way ahead on Baltic maritime defense

Given the limited resources available to the Baltic states (even though they have been significantly expanded and are in line with the commitments made to NATO), along with other investment priorities, the individual contributions by the Baltic states to defense and deterrence in the maritime domain will continue to be constrained. Furthermore, generating and sustaining many naval capabilities, such as ASW, air defense, and surface warfare is very expensive and therefore out of reach for the Baltic states. However, if the efforts of the Baltic states were broadly aligned with each other as well as with the efforts of NATO and larger nations in the Baltic Sea region, Estonia, Latvia, and Lithuania could significantly contribute to NATO’s ability to operate in the maritime domain of the Baltic Sea region and help keep the approaches to the Baltic states open for seaborne reinforcements.

In light of this, the Baltic states should consider the following resource-informed recommendations:

Strategy and Regional Cooperation

Align Baltic efforts with NATO’s emerging maritime focus. Real attention to the maritime domain is emerging within NATO, and future command structure updates are highly likely to have a maritime focus. Furthermore, it is probable that NATO will update its Alliance Maritime Strategy in the near future. The development of Baltic maritime capabilities and roles should be closely aligned and supportive of the broader evolution of the Alliance’s structures, capabilities, and concepts for maritime operations, in particular those aspects focused on collective defense and deterrence. In addition, given the unique nature and role of the Baltic Sea in the new European security environment, NATO should consider developing a maritime defense strategy for the Baltic Sea, which outlines key tasks, needed capabilities , command and control arrangements, and how the maritime domain aligns with NATO’s broader defense and deterrence planning for the region.

Cooperation with Key Baltic Sea states. In aggregate, the nations of the Baltic Sea region bring a substantial range of naval capabilities, including anti-submarine warfare, air defense, sub-surface warfare, and electronic warfare. In addition, the new naval investments in the Baltic Sea region will help cover some of the capabilities gaps that are left by the limited resources of the Baltic states themselves. In this context, Germany is emerging as a regional leader of sorts in terms of orchestrating regional maritime cooperation in capabilities development and exercises. In the coming years, this German role in the Baltic Sea will likely be further strengthened with the Baltic Sea Maritime Component Command in Rostock, which will provide command and control capabilities for operations.5See Magnus Nordenman, “Back to the North: The Future of theGerman Navy in the New European Security Environment,” Atlantic Council, April 4, 2017,

The Baltic states should therefore consider cooperation opportunities with Germany in the maritime domain, in order to grow capabilities and ensure alignment with the efforts of other nations in the Baltic Sea region.

A US Naval Role in the Baltic Sea. In a crisis scenario in the Baltic Sea region, US naval forces would play a key role in delivering long-range strike, electronic warfare, and sea-based air defense capabilities for the NATO response. Furthermore, US amphibious forces, along with allied counterparts, could play a key role in the reinforcements package for the Baltic States. Also, the US can contribute undersea sensors and mine warfare capabilities to regional defense efforts. US naval forces could also play a very helpful role in peacetime to generate further regional cooperation and provide a rotational presence in the Baltic Sea, which would contribute to the Alliance’s deterrence posture in the region6.See Bruce Stubbs, “The US Navy Has a Role in the Baltic,” Proceedings Magazine, September 2017, 47-51.

In practical terms, a US naval presence in the Baltic Sea should be focused on capabilities development to address either US or allied shortfalls. US-Baltic naval cooperation could, specifically, focus on MCM and mine warfare (for additional details see below in Roles and Capabilities); an area of deep Baltic expertise, but where the United States is currently developing new concepts and approaches. A US Navy littoral combat ship with an MCM mission package would be a suitable platform for this cooperation.

Give NATO Force Integration Units a stronger maritime dimension. Along with eFP groups, each Baltic nation currently hosts a NATO Force Integration Unit (NFIU), which is responsible for preparing and facilitating the deployment of allied forces and the Very High Readiness Joint Task Force (VJTF) to the Baltic region. The role of the NFIU could be further strengthened by giving it more of a maritime dimension in terms of staff and focus.

Roles and Capabilities

Sustain the MCM role. The Baltic states are recognized leaders in mine hunting in littoral areas; a capability that is relevant to the broader Alliance and may still find uses in future expeditionary operations. More importantly, the MCM capability is directly relevant to the new security environment in the Baltic Sea region. The use of sea mines by Russia, overtly or covertly deployed, would present a real challenge to NATO’s maritime operations in the Baltic Sea, and even a few mines would suffice to delay reinforcements or restrict naval operations. Sustaining and further developing the Baltic states’ MCM capabilities are therefore a direct contribution to NATO’s efforts to defeat Russia’s A2/AD strategy in the Baltic Sea region.

Consider a mine warfare mission for the Baltic navies. Russia’s access to the Baltic Sea is constrained and during a crisis or war could be further made difficult by the use of sea mines, thereby frustrating parts of Russia’s A2/AD efforts before they could be fully deployed. The location of the Baltic states would also mean that the Baltic navies could serve as “first responders” in the event of a military crisis in the region. Weapons such as mines are relatively cheap to procure and maintain and can be deployed from a range of ships, even converted fishing vessels.

Bolster maritime domain awareness with unmanned systems. The Baltic states, along with the other nations of the region, urgently need to enhance maritime domain awareness to build a better picture of the dynamics and patterns in the maritime environment. A cost-effective way could be the use of small unmanned aerial systems for coastal surveillance with cameras and other sensors.

Consider a coastal defense capability. The Baltic states are vulnerable to amphibious and nearshore operations. This threat can be answered with the development of a modest coastal defense capability. This could include relatively cheap short-range and light anti-ship missiles, which can be made highly mobile when carried by light or medium trucks; such light coastal defense missiles could also be mounted on and fired from small patrol boats.

There are examples of current systems of this type, which include Hellfire missiles as well as the SpikeER missile. Both were originally anti-tank systems that have been adapted to a coastal defense role. These systems are in use by other armed forces in the broader region, namely Norway, Sweden, and Finland. The Spike system is already in the inventory of the Latvian and Lithuanian armed forces as an anti-tank capability.

Enable reinforcements and a forward naval presence. The Baltic states enjoy the use of a number of good ports in Estonia, Latvia, and Lithuania, which are currently engaged in processing high volumes of cargo and shipping. Indeed, some of them have already been utilized to flow NATO members forces into the region for training and exercises. The Baltic port infrastructure should be further reviewed in order to ensure their suitability for receiving reinforcements, and their port security arrangements strengthened against both sabotage and cyber attacks. NATO must also more fully use the ports for exercises in order to build familiarity with the infrastructure available, and to allow any shortcomings that need to be addressed to emerge now in order to allow an effective use of the ports before or during a crisis.

The Baltic states and NATO should consider the creation of a hub for a forward naval presence in the Baltic region. Such a hub would not only be used for reinforcement shipments before or during a crisis, but could also host NATO member naval forces on a rotational basis for training and exercises in the region and with the Baltic navies and other forces. The port of Liepaja in Latvia, for example, would be suitable for this type of arrangement. It is a commercial port, and the Latvian navy already operates out of the area. The geographical location of Liepaja would allow NATO naval forces space for operational maneuver, something that is not available closer to Kaliningrad or in the Gulf of Riga, and that is a crucial consideration given Russia’s A2/AD network in the region.

A full-fledged NATO maritime hub in Liepaja would require a number of functions and infrastructure features to be functional both as a seaport of debarkation and as a staging area for a forward naval presence. This includes effective seaport management, arrival and departure coordination, movement control, robust hazardous cargo handling, tug support, maintenance, as well as port security and force protection by the host nation. The infrastructure requirements, meanwhile, include deep draft piers, on- and off-loading equipment, marshalling areas, munition and fuel storage, and interfaces with road and rail networks for onward movement.


Since 2014, NATO and the Baltic states have made significant progress in strengthening collective defense and deterrence in the Baltic Sea region. The Baltic region now plays host to NATO’s enhanced forward presence groups, which provide a muchneeded trip wire and serve as the basis for further development of capabilities and operations in the ground domain. It is now time for the Baltic states and NATO to comprehensively consider the Baltic Sea maritime domain and the threats and challenges there. Northern Europe is sure to remain a groundcentric domain in terms of defense and deterrence for NATO, but the maritime domain can play an important supporting role, not least as an avenue of approach for NATO reinforcements and long-range strike from the sea. While there are more national resources available for defense in the Baltic states, the room for the development of maritime capabilities will remain limited given other priorities. A resource-informed way forward for the Baltic states in the maritime domain therefore lies in the transition to a coastal defense force as a contribution to restricting Russian operations in the Baltic Sea and close alignment with the efforts of the broader Alliance and key NATO members in the region.

Magnus Nordenman is the director of the Transatlantic Security Initiative and deputy director of the Scowcroft Center for Strategy and Security at the Atlantic Council.

Related Experts: Magnus Nordenman