NATO–EU Strategic Priority: Maritime Security & Undersea Infrastructure Protection

Maritime security and the protection of undersea infrastructure have become central tests of how resilient European and allied democracies really are. Gas pipelines on the seabed, fibre-optic cables carrying almost all international data, and the dense clusters of offshore platforms and wind farms form an invisible but essential layer of the European security and economic system. The sabotage of the Nord Stream pipelines and subsequent cable incidents in the Baltic and North Sea have shown that these assets are no longer exposed only to accidents or natural risks, but to deliberate, covert hostile action. At the same time, Russian submarine and “research” activities close to critical routes, the rapid spread of unmanned underwater vehicles and the integration of cyber operations with physical sabotage have widened the spectrum of possible threats. For NATO, the EU and national governments, this means that sea control can no longer be understood only in terms of ships and fleets, but must include the ability to monitor, defend and if necessary rapidly repair vital infrastructure on and under the seabed. The question is whether allied institutions, industries and research systems are adapting fast enough to give credible protection to these assets and to remove the incentives for hybrid attacks in the maritime domain.

The report available to subscribers examines this question along a complete political–strategic and techno-industrial chain. It opens by reconstructing why “Maritime Security & Undersea Infrastructure Protection” has been elevated to a formal strategic priority, linking it to NATO’s Strategic Concept, the Alliance Maritime Strategy, the EU Maritime Security Strategy and recent national reviews. It then translates this into the operational dimension, explaining how maritime domain awareness, anti-submarine warfare, naval task group integration and undersea infrastructure surveillance are being reorganised in a multidomain architecture that combines ships, submarines, aircraft, satellites, cyber and unmanned systems. A central section derives the concrete tactical and capability requirements, from UUV/UAV surveillance, sonar networks and seabed sensors to maritime patrol aircraft and repair capacity, showing where current shortfalls lie. The following chapter analyses how NATO, the EU and national authorities are using regulations, funding programmes and procurement plans to implement this priority and shape industrial behaviour. A dedicated section maps the structural bottlenecks and strategic dependencies that still constrain allied freedom of action, including supply-chain vulnerabilities and production limits. The report closes by outlining what this means for companies, technologies, research actors and investors, indicating which segments of the defence–technology–capital ecosystem are becoming central and where medium- to long-term opportunities and risks are emerging.

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Strategic Rationale and Political Context

In recent years, NATO, the European Union and allied nations have elevated maritime security – specifically the protection of undersea critical infrastructure – to a core strategic priority. This shift is rooted in a sobering threat landscape. Russia’s renewed aggression and its modernized Navy, equipped with advanced submarines and underwater systems, pose a direct challenge to Allied security in the undersea domain[1][2]. The wake-up call came in September 2022, when explosions sabotaged the Nord Stream gas pipelines on the Baltic seabed, starkly exposing Allied vulnerabilities[3][4]. Subsequent incidents – from mysterious cable cuts in the North Sea and Baltic in 2023 to intensified Russian naval probing of offshore infrastructure – reinforced that undersea energy pipelines, internet cables and other seabed installations are strategic targets in hybrid warfare[3][4]. As a result, protecting these assets has surged to the top of the Euro-Atlantic security agenda[5].

Allied leaders recognize that freedom of navigation and secure maritime infrastructure are foundational to the stability and prosperity of liberal democracies. NATO’s 2022 Strategic Concept explicitly underscores that “maritime security is key to our peace and prosperity” and commits the Alliance to “deter and defend against all threats in the maritime domain, uphold freedom of navigation, secure maritime trade routes and protect our main lines of communications.”[6]. Undersea fiber-optic cables carry the vast majority of global data traffic, binding economies and societies; likewise, seabed pipelines convey critical energy supplies. Any disruption could cripple communications, markets and public services across multiple states in an instant. The UK government’s 2025 National Security Strategy bluntly notes that Britain depends on subsea cables for 99% of its international digital data and on seabed pipelines for three-quarters of its gas – meaning “territorial security begins at sea”[7]. An attack on these invisible arteries would not only damage economies but also erode public trust in governments’ ability to guarantee basic connectivity and energy – a potentially destabilising blow to democratic resilience. Thus, safeguarding undersea infrastructure is seen as essential to national resilience and to upholding the international order against coercion.

Beyond their economic importance, subsea assets have taken on a heightened strategic relevance in the tense geopolitical climate following Russia’s invasion of Ukraine. Western officials suspect Moscow sees clandestine sabotage of cables or pipelines as a way to impose costs and sow chaos below the threshold of open warfare[8]. Such hybrid operations could fragment Allied decision-making or deter military deployments by threatening reinforcement routes and communications. Indeed, NATO parliamentarians warned back in 2019 that Russia’s submarine threat “presents a clear, immediate danger” not only in traditional military terms but also as part of a hybrid strategy to “undermine and split the Alliance,” including by targeting undersea cable networks[9][10]. By late 2022, this danger shifted from theory to reality. In response, NATO and the EU have sharpened their focus on undersea infrastructure protection as integral to credible deterrence. Allies judge that visibly hardening these assets will signal to adversaries that hybrid attacks will neither divide Allied nations nor go unanswered[11][12]. In short, resilience has become a pillar of deterrence: the goal is to deny adversaries the temptation to exploit maritime vulnerabilities and thereby reinforce the overall stability of the Euro-Atlantic security order.

This priority is firmly anchored in top-level strategic guidance. NATO’s 2022 Strategic Concept and 2023 Vilnius Summit declarations both stress the need to protect critical infrastructure, including undersea, as part of collective defence[13][14]. NATO’s new Alliance Maritime Strategy (approved 2025) crystallises this, highlighting the Alliance’s commitment to “safeguard vital sea lines of communication and protect critical infrastructure, with a focus on securing undersea infrastructure.”[15][16] Deterrence and Defence of the Euro-Atlantic Area (DDA) plans explicitly factor in scenarios like attacks on seabed cables, ensuring NATO can respond to such hybrid aggression[17][18]. The EU’s Strategic Compass for Security and Defence (2022) similarly identifies the maritime domain as a priority and calls for bolstering resilience against threats to European infrastructure. Following Nord Stream, the EU urgently updated its Maritime Security Strategy in 2023, which the Council affirmed with stark language: “Protecting critical infrastructure in the maritime domain, such as gas pipelines, undersea internet cables and offshore wind farms, is a top priority for the EU.”[13] The strategy’s action plan directs EU members to develop regional surveillance plans, innovative technologies and interoperable unmanned systems to guard undersea networks[19]. National strategies echo the same themes. For example, the UK’s 2025 Strategic Defence Review elevates undersea infrastructure security to a core mission, assigning the Royal Navy a “leading role” in countering Russian submarines and spy ships threatening cables and pipelines under a new operation “Atlantic Bastion”[20]. London even revised its rules of engagement so warships can more assertively track and interdict vessels suspected of undersea sabotage[21]. Meanwhile the ten-nation Joint Expeditionary Force led by the UK has intensified patrols in the North and Baltic Seas to deter covert attacks on subsea assets[22].

Geographically, this priority has an “Alliance-wide” scope with particular urgency in European waters. The Baltic and North Seas are focal points – both dense with data cables, pipelines and offshore energy platforms, and heavily trafficked by Russian naval units transiting to the Atlantic[23][12]. Nord Stream lay in the Baltic; subsequent cable cuts occurred in the Baltic and North Sea; and Western navies have tracked unusual activities by Russian “research” vessels near Nordic undersea infrastructure[24][25]. In the North Atlantic, the risk of Russian submarines severing transoceanic cables or targeting naval reinforcement routes revives a Cold War-era concern with new urgency[26]. Southern Europe is not exempt: the Mediterranean contains critical gas pipelines from North Africa and the Middle East to Europe, as well as growing undersea data links, amid Russian naval presence there too. Even the High North and Arctic are relevant, as climate change opens new sea lanes and Russia and China increase their activity – prompting calls for enhanced NATO maritime presence to secure undersea infrastructure in those harsher environs as well[27][28]. Overall, Allied officials emphasise a 360-degree approach: every maritime flank, from the Baltic and Black Seas to the North Atlantic and Arctic, must be monitored for hybrid threats to infrastructure[29][30].

The time horizon for this priority spans the immediate to the long-term. The Nord Stream blasts injected a sense of immediacy – leading to rapid remedial steps in 2022–2024 such as heightened naval patrols and emergency infrastructure inspections[11][12]. Yet truly robust undersea security will require sustained efforts over the coming decade: investing in new capabilities, hardening networks and developing doctrine. NATO and EU planning documents generally set targets toward 2030 for improving resilience and plugging capability gaps in this arena[31][32]. The intent is to progressively raise the costs and reduce the benefits of any hostile underwater action, thereby bolstering deterrence in both peace and crisis. By protecting the connective tissue of the global economy and Allied military networks, NATO and the EU aim to strengthen the credibility of deterrence (by denying adversaries cheap victories) and reinforce the resilience of democratic societies (by ensuring continuity of vital services under duress). In sum, the political mandate is clear: Allied nations will not tolerate interference with their undersea lifelines, and they are marshaling the diplomatic, military and industrial tools at their disposal to safeguard them[12][33].

Operational Dimension and Multidomain Architecture

Translating this strategic mandate into action, NATO, the EU and Allied states are retooling their operational concepts and force posture to secure the maritime underbelly of the Alliance. The effort is inherently multidomain. While the mission centers on the maritime domain – keeping the seas and seabed under Allied control and surveillance – it integrates capabilities from air, space, cyber and the information domain in a tightly coordinated architecture[33][34]. The operational goal is twofold: persistent awareness (to deter or detect any threat to maritime infrastructure before damage occurs) and rapid response (to neutralize threats or repair damage swiftly if an incident happens). Achieving these goals requires weaving together naval forces, air assets, satellites, cyber defences and even civilian partners into a unified protective network.

At sea, NATO is adapting both its standing naval forces and regional deployments. The Alliance’s Standing Maritime Groups – multi-national flotillas that patrol European waters – have been tasked explicitly with deterring and “detecting and countering threats to maritime security, including maritime critical infrastructure.”[35]. These standing naval groups (like Standing NATO Maritime Group 1 in the North/Baltic Sea and SNMG2 in the Mediterranean) now regularly include missions to monitor key undersea infrastructure corridors. For example, after the Nord Stream attack, NATO countries surged additional warships and submarines into the Baltic, North Sea and North Atlantic to guard pipelines and cables, operating under national command but coordinated through NATO’s maritime headquarters. This ad-hoc surge is evolving into a more enduring posture. In January 2025, Allies launched Operation “Baltic Sentry” – a NATO-led multi-domain activity in the Baltic Sea explicitly designed to “enhance NATO’s military presence” and improve responsiveness against undersea infrastructure attacks[36]. Baltic Sentry brings together warships and Maritime Patrol Aircraft (MPA) to increase patrol coverage, and notably it deploys new naval unmanned systems (drones) to extend surveillance beneath and above the waves[37]. Such integrated task groups blend surface combatants (e.g. frigates equipped with sonar and helicopters), submarines, MPAs and unmanned underwater or aerial vehicles into a single operational package, all sharing information in real time.

Command and control for these efforts leverages NATO’s existing maritime command structure, reinforced with new coordination cells. NATO’s Allied Maritime Command (MARCOM) in Northwood, UK remains the hub for maritime operations, including infrastructure protection. At the 2023 Vilnius Summit, Allies agreed to establish a dedicated Maritime Centre for the Security of Critical Underwater Infrastructure under MARCOM’s auspices[14][38]. Launched in 2023, this center serves as a fusion node for threat intelligence, surveillance data and expertise on undersea infrastructure security[38][39]. It coordinates closely with a parallel NATO Critical Undersea Infrastructure Coordination Cell, created at Headquarters to connect military efforts with civilian operators and industries[40][29]. Through these mechanisms, NATO seeks to break traditional stovepipes – ensuring, for instance, that if a private cable company detects an anomaly on a fiber-optic line, or if a national coast guard spots a suspicious vessel near an offshore pipeline, the information is instantly shared to cue NATO military assets. Exercises and command-post drills now routinely inject undersea disruption scenarios to rehearse this coordination. The emphasis on information sharing extends beyond NATO’s walls: since 2022 a NATO-EU Task Force on Resilience has been working to improve cross-organization communication on threats to energy, transport and digital infrastructure[41][42]. A key recommendation has been to better link NATO’s military reporting with EU civilian networks (like the EU Maritime Security Single Point of Contact system)[43][44].

The operational domain integration is also evident in how Allies employ space and cyber assets. Satellite reconnaissance and commercial space-based sensors have been harnessed to enhance Maritime Domain Awareness (MDA). High-resolution imaging satellites and radar satellites (SAR) can monitor vessel movements along undersea cable routes or around platforms, even at night or through clouds. NATO’s concept of “Digital Ocean” envisages fusing such data with traditional maritime sensors to achieve persistent situational awareness at sea[45][46]. By 2024, NATO and the EU were actively coordinating to use the EU’s Copernicus space program and commercial imagery to surveil critical maritime zones for anomalies[47][48]. Cyber domain integration is equally crucial: many undersea infrastructure threats can originate or be amplified via cyber means (for instance, hacking the control systems of offshore platforms or disrupting the data carried on cables). Thus, NATO’s joint cyber defence teams and EU cybersecurity agencies are on alert to detect cyber-attacks that could foreshadow or accompany a physical sabotage[11]. Protecting the data integrity and network management of undersea infrastructure is part of the broader operational picture. In parallel, information operations are considered: Allies know that in the aftermath of any mysterious cable outage or pipeline blast, controlling the narrative is vital to prevent adversary disinformation. Therefore, NATO’s stratcom and EU institutions have plans to rapidly attribute and publicly expose malicious undersea incidents when evidence permits – denying adversaries the cloak of ambiguity they seek in hybrid campaigns.

Allied states have also developed regional frameworks to implement this priority. Northern Europe has taken a lead, given the concentration of Russian naval activity there. The UK-led Joint Expeditionary Force (JEF), comprising ten NATO nations around the North Sea and Baltic, has made undersea infrastructure protection one of its core missions in peacetime. The JEF nations established a Baltic Undersea Security working group and conduct exercises focused on joint responses to pipeline or cable attacks[22]. At JEF’s operational HQ in Northwood (collocated with NATO MARCOM), personnel from member countries now continuously share maritime surveillance findings – for example, tracking Russia’s so-called “ghost ships” or “shadow fleet” of covert vessels that might menace subsea cables[49]. Meanwhile in the South, NATO’s Operation Sea Guardian in the Mediterranean has expanded its remit beyond counter-terrorism to include monitoring of critical undersea connectors like gas pipelines from Algeria and Libya to Europe. In the Atlantic, the reactivation of the US Navy’s Atlantic 2nd Fleet and NATO’s Joint Force Command Norfolk in recent years was driven largely by the need to secure transatlantic sea lines (both shipping lanes and the cable grid on the Atlantic floor)[26]. These commands now work hand-in-hand with Allied navies and intelligence services to watch the Greenland-Iceland-UK (GIUK) gap and other chokepoints for unusual undersea activities. For instance, when in early 2023 an undersea cable between Svalbard and mainland Norway was found severed, Norwegian and British forces under NATO coordination quickly deployed survey ships and patrol aircraft to investigate and secure other nearby infrastructure[50][51].

Crucially, this priority is multidomain by design – not a siloed “naval-only” effort. NATO’s operational concept stresses cross-domain synergy: air and maritime forces working together for Anti-Submarine Warfare (ASW) and reconnaissance, space and cyber providing enabling support, and land-based command centers fusing the intelligence. A concrete example is the deployment of Maritime Patrol Aircraft from NATO air bases to augment naval coverage. These high-end aircraft (like the P-8A Poseidon operated by numerous Allies) can rapidly sweep vast ocean areas with sonars and magnetic detectors, cueing naval vessels or drones if they find a contact. In Baltic Sentry, a coordinated cycle of P-8 patrols, surface ship patrols and periodic satellite scans is used to maintain near-real-time awareness around critical pipeline routes[33]. Data links and NATO C2 systems ensure that an alert from any sensor – be it a seabed hydrophone detecting an explosion, or a satellite spotting an unmarked ship loitering – is shared across the force instantly. Commanders employ a layered response posture: for example, if an underwater contact is detected near a cable, an unmanned underwater vehicle might be sent to inspect, while an MPA provides overwatch and a surface warship stands ready to intervene. This layered, multitier force architecture is guided by NATO joint doctrine (e.g. the Alliance’s revised ASW doctrine and emerging Seabed Warfare concepts) which emphasise seamless integration of all tools to counter undersea threats[52][53].

The EU contributes to the operational dimension in complementary ways. While the EU has no standing navy of its own, it facilitates multinational cooperation and capacity-building among member states. Under the updated EU Maritime Security Strategy action plan, the Union launched in 2024 an annual EU Maritime Security Exercise involving naval and coast guard assets from many countries[54]. These drills specifically include scenarios of hybrid attacks on offshore infrastructure, thereby improving civilian-military coordination and interoperability of national forces. The EU’s Coordinated Maritime Presences (CMP) concept, used in regions like the Gulf of Guinea, is being considered for European home waters as well – essentially pooling European naval patrol resources to ensure no gap in coverage of critical sea areas[55]. Additionally, EU agencies like the European Maritime Safety Agency (EMSA) are expanding their monitoring functions. EMSA operates drones and satellite services to monitor maritime traffic for safety; now this data is shared for security purposes too, such as detecting unknown craft near undersea cable landing sites. The Union has also encouraged regional formats – for instance, a Baltic Sea Security Compact among coastal states – to jointly surveil infrastructure. In late 2023, countries around the Baltic and North Sea, including Norway (a NATO member outside the EU), signed agreements to coordinate their seabed patrol efforts and exchange live information on potential threats[56][57]. This reflects a pragmatic understanding that protecting underwater infrastructure transcends any single nation or institution: it demands a network-of-networks approach tying together NATO’s military might, the EU’s civilian instruments, and national capabilities.

In operational terms, Allied forces are preparing for a range of missions under this priority. These span the spectrum from peacetime security operations – e.g. routine patrols, inspections and presence missions to deter malign activities – through crisis response (locating and neutralizing mines or submersibles if intelligence suggests an imminent threat), up to conflict scenarios where securing sea lines and repairing damaged infrastructure would be critical to sustain Allied operations. Notably, protecting undersea infrastructure is now woven into NATO’s new regional defence plans for collective defence on the Eastern Flank and North Atlantic[26][18]. For instance, a high-intensity conflict scenario in Northeast Europe considers that Russia might try to cripple NATO communications or slow reinforcement by attacking cables/pipelines; accordingly, NATO’s plan would involve pre-emptively deploying ASW forces to hunt hostile submarines and deploying engineering teams to enable quick repair of infrastructure[17][18]. In sum, what began as an urgent reactive patch in 2022 has matured by 2025 into a comprehensive operational architecture: one that is preemptive, integrated across domains, allied-wide, and closely synchronized with political and civilian instruments. This architecture operationalizes the strategic priority of maritime infrastructure protection, translating it into concrete vigilance and preparedness on, above and below the seas.

Tactical and Capability Requirements

Beneath the broad operational concepts lie very concrete tactical requirements and capability needs. To make Allied promises of undersea infrastructure protection credible, militaries require specific tools: persistent surveillance systems to see threats, effective ASW assets to track and engage threats, hardened networks to monitor infrastructure, and agile forces to respond across wide maritime spaces. These needs drive a range of capability development programs across NATO and the EU. In functional terms, the priority demands strength in several capability families – most prominently sensing, command and control, effectors (weapons and interceptors), mobility and reach, protection & resilience, and sustainment – all tailored to the maritime and undersea environment.

Surveillance and sensing are the linchpin. Allies must be able to detect anomalies in vast ocean areas and at great depths, often in real time. This has led to renewed focus on underwater sensor networks and platforms. Navies are deploying advanced sonar systems on multiple vectors: hull-mounted sonars and towed arrays on surface ships, low-frequency active sonars on maritime patrol aircraft, dipping sonars on helicopters, and fixed undersea sensor arrays in chokepoints. However, given the oceans’ expanse, traditional sensors alone are not enough. A key requirement is for persistent, unmanned surveillance using Uncrewed Underwater Vehicles (UUVs), Uncrewed Surface Vessels (USVs) and Uncrewed Aerial Vehicles (UAVs) specialized for maritime ISR[58][59]. Small and medium UUVs can patrol around critical pipeline or cable routes autonomously, using side-scan sonar and cameras to detect tampering or suspicious objects. The tactical priority of “UUV/UAV maritime surveillance” reflects this need for robotic sentries under and above the waves. These vehicles must have significant endurance (measured in dozens of hours or more), high-quality sensors and secure communication links to send back data. The NATO Parliamentary Assembly foresaw this back in 2019, urging Allies to invest in “new sensor technologies and the integration of autonomous unmanned vehicles (AUVs) into anti-submarine missions”[58]. Today, that vision is becoming reality – for example, NATO’s Baltic Sentry includes a “small fleet of naval drones” working alongside manned ships and aircraft[33]. EU collaborative projects are also delivering: under the PESCO framework, a consortium of seven nations launched the Critical Seabed Infrastructure Protection project to develop a system of stationary seabed sensors and deployable UUVs for monitoring EU undersea infrastructure[60][61]. This points to a near-future tactical picture where networks of seabed hydrophones, optical fiber sensors, and patrolling drones provide continuous ears and eyes beneath the surface.

Another critical capability is Maritime Domain Awareness fusion – turning all those sensor inputs into a coherent picture and getting it to operators rapidly. Thus, robust Command, Control, Communications, Computers & Intelligence (C4I) systems are required. NATO and Allies are updating their maritime C2 systems to ingest new data streams (like real-time feeds from unmanned drones or civilian sensors) and to share a common operating picture across navies. Interoperability standards such as STANAGs have been developed to ensure, for instance, that a Polish naval operations center can receive and display sensor data from a German or Norwegian undersea drone on a NATO network. The sheer volume of data from persistent surveillance also creates a demand for data analytics and AI tools – for example, using machine learning to filter out biologic or civilian noise from sonar reports and flag truly suspicious contacts. This is a budding tactical capability: trials are underway at NATO’s Centre for Maritime Research and Experimentation (CMRE) to apply AI in classifying undersea sounds, which could dramatically reduce false alarms and reaction times[59][62]. In the same vein, “sensor fusion” across domains is a must-have: a single undersea incident might be detected in acoustic data, satellite imagery and cyber logs in parallel, so systems that rapidly fuse those into one incident report are being fielded. The NATO Maritime CUI Centre serves as a node for such fusion at the strategic level; tactically, onboard command systems on ships and MPAs are being upgraded to handle multi-source inputs.

On the anti-submarine warfare (ASW) and interception side, the priority demands rejuvenating a spectrum of effectors. The most capable platform to hunt enemy submarines is often another submarine; accordingly, Allies are investing in their submarine fleets (e.g. new quiet diesel-electric subs co-developed by Germany and Norway) and improving integration of subs into NATO patrol patterns. Surface combatants like frigates and destroyers need ASW proficiency: this includes fitting or upgrading them with towed sonar arrays, anti-submarine rockets/torpedoes, and embarked helicopters. A noted shortfall identified was that some Allied navies lacked essential ASW kit – for instance, Denmark’s navy had no towed array sonars on its frigates, falling short of NATO’s capability targets[63]. Moves to address this are underway, driven by NATO Defence Planning Process (NDPP) targets that call for each Ally to contribute to ASW coverage. Maritime patrol aircraft are another key effector, armed with air-launched torpedoes and depth charges. NATO has acknowledged a reduction in MPA capacity over the past two decades and is working to reverse it[64]. Several Allies (UK, Norway, US, Germany, Italy) have acquired or are acquiring P-8 Poseidon MPAs, significantly bolstering the Alliance’s ASW reach[10]. The tactical requirement is to ensure sufficient MPA availability such that, during heightened threat periods, multiple aircraft can maintain patrol orbits over critical undersea corridors around the clock. In line with DFM’s tactical priorities, ensuring “Maritime Patrol Aircraft coverage” is essentially about buying enough planes, training enough crews, and prepositioning them at key airfields (like Lossiemouth in Scotland, Keflavik in Iceland, or Nordholz in Germany) to rapidly deploy where needed.

As important as traditional ASW assets are, Allies recognise new classes of threats that require novel countermeasures. Not only do we face hostile submarines, but potentially uncrewed threat vehicles – for example, an unmanned mini-sub laden with explosives or a submersible drone dispatched to tap or sever a cable. The requirement to counter such systems has catalysed interest in “seabed warfare” technologies. These include deployable underwater drones that can intercept other drones, or smart mine-like devices that could be placed around critical infrastructure and programmed to detect and disable intruders. While still in development, NATO and EU studies have highlighted the need for “reactive capabilities in Seabed Warfare (SBW) scenarios” up to depths of several kilometers[65][66]. In effect, Allied forces may need undersea analogues to an air defence system – but for the deep ocean, creating protective bubbles around vital nodes. This is a cutting-edge tactical challenge: current ASW weapons like homing torpedoes are designed for engaging manned subs, not small drones in shallow waters or attached to cable repeaters. Research is ongoing into new sensor-effector combos such as underwater gliders with intercept payloads or non-lethal options (e.g. entangling nets for UUVs). Until those emerge, the interim approach is to leverage the improved surveillance to catch threats early and neutralize them with existing assets (e.g. sending a dive team or using a ship’s small remotely operated vehicle to investigate and neutralize a suspicious object on a cable).

Another set of requirements revolves around infrastructure monitoring and hardening. It is not enough to hunt adversaries; Allies also seek to make the infrastructure itself more resilient and tamper-evident. This drives capability needs in underwater sensors and networks. For instance, one concept is deploying fiber-optic acoustic sensors along pipeline or cable routes – effectively turning the cable into a long listening device that can detect disturbances. The EU, through the European Defence Fund, has invested in projects to mature fiber-optic hydrophone technology for wide-area underwater surveillance[67][68]. Such systems can pick up the distinct vibrations of a ship or submersible approaching a cable, and do so passively and covertly. The EU’s CASSATA project is enhancing covert multi-sensor platforms, while SCUALE is improving materials for underwater acoustics – both aimed at better detecting threats to subsea infrastructure[68]. These efforts align with a tactical push for “undersea infrastructure sensor grids,” meaning integrated networks of fixed and mobile sensors guarding high-value assets. We see early deployments: Norway, for example, has set up a surveillance center that unites military sonar feeds with inputs from offshore industry sensors to monitor activity around oil/gas pipelines[29]. The Italian Navy’s new Undersea Infrastructure Surveillance Centre similarly blends civilian and naval data to watch the Mediterranean seabed[29]. The capability challenge is ensuring interoperability and coverage – connecting disparate sensors into one network and filling any blind spots (for example, the gaps between national territorial waters in international waters). On the protection side, physical hardening of infrastructure is also considered where feasible. Tactical measures include embedding cables deeper into seabed in vulnerable chokepoints, adding concrete coating or armor to pipelines, and installing remote-operated valves to shut off sections of pipeline quickly if rupture is detected (minimizing damage). While these fall largely to industry, military input helps prioritize which segments get such treatment based on threat intelligence.

Tying all these capabilities together is the need for resilient communications and data infrastructure to support operations. Ironically, protecting undersea communications relies on having secure communications. Thus, a capability requirement is hardened, multi-path communication for forces – so that even if a primary fiber-optic cable is cut, military comms can fail over to satellite or HF radio. NATO is improving its satellite communication assets and exploring backup networks (including potentially laser communications or linking into commercial constellations) to ensure C2 isn’t paralyzed by any single infrastructure attack. Cyber security of these C2 systems is another requirement: tactical units must have confidence that the data they receive hasn’t been spoofed by an adversary cyber-attack. This is prompting the adoption of “zero-trust” architecture and strong encryption even in deployable naval networks, much like NATO’s tactical networks on land[59]. For instance, if a sensor buoy is reporting an intrusion, authentication measures verify it’s a genuine signal and not injected false data.

Each of these requirements connects to specific technology domains, including emerging and disruptive tech (EDTs). Artificial intelligence is tapped for better pattern recognition in ocean data and autonomous control of drones. Autonomy itself is at the heart of unmanned maritime vehicles – with advances in automation enabling drones to perform “dull, dirty, dangerous” surveillance that manned crews can’t sustain[59][69]. Quantum technology looms on the horizon, potentially offering next-generation sensors (for example, quantum gravimeters that might detect submerged objects by tiny gravitational anomalies) – Allied research programs are monitoring these developments, though quantum sensing is still nascent. Materials science innovations, like new composites and pressure-tolerant electronics, are critical to build UUVs that can dive deeper (the EU’s calls explicitly seek technologies to operate UUVs down to 6000m depth, far beyond current limits[70][71]). Cyber tools are double-edged – while they pose threats, they also enable remote monitoring and rapid data crunching if applied defensively. NATO’s adoption of secure cloud computing in its Digital Ocean initiative is one example of leveraging advanced IT for maritime situational awareness[45][46].

Identifying capability shortfalls has been a sobering process. NATO’s assessments around 2018–2020 concluded that Allied ASW capabilities had atrophied considerably since the Cold War[72][73]. The number of Allied frigates and patrol aircraft equipped for ASW had dropped, and stockpiles of sonobuoys, torpedoes and spare parts were limited. A 2019 NATO Parliamentary report warned the Alliance was at risk of having its ASW capacity “overwhelmed” by new Russian sub deployments if major investments were not made[73][74]. Since then, progress has been made – e.g. the procurement of dozens of new MPAs and the standing up of new ASW centers of excellence – but gaps remain. One critical shortfall area is trained personnel: ASW is a complex art, and many navies had to rebuild skilled cadres of sonar operators and undersea warfare officers. Efforts are ongoing through NATO training (exercises like Dynamic Mongoose in the North Atlantic focus on honing ASW skills among Allied crews)[75]. Another shortfall is in seabed warfare capabilities – until recently, virtually no navy had dedicated units or equipment for seabed operations beyond minesweeping. The development of those capabilities is now urgent but will take time; Allies acknowledge that fully monitoring and defending thousands of kilometers of seabed is an immense undertaking still in its infancy[52][53]. The EU and NATO capability planners have also highlighted industrial shortfalls: for instance, Europe has limited production capacity for certain undersea tech like advanced sonar transducers and fiber-optic cables with built-in sensors[76][77]. These shortfalls are being prioritized in research and procurement plans, with NATO’s NDPP identifying ASW and maritime ISR as high-priority investment areas for the upcoming cycle[78].

In summary, the tactical and capability requirements to fulfill this strategic priority are extensive and technically demanding. They range from age-old needs (more ships, submarines, patrol aircraft and sonars to find and fight enemy subs) to brand-new ones (unmanned underwater surveillance grids, AI-driven data fusion, and tools for deep-ocean defence). What unites them is a focus on persistence, integration and resilience: persistence in surveilling the domain 24/7, integration of many platforms and nations into a cohesive whole, and resilience to keep operating even if adversaries attempt disruptive attacks. Allied publics and decision-makers have been made acutely aware that without these capabilities, their critical lifelines under the sea remain exposed. This has created strong momentum – and indeed pressure – to deliver the required military and dual-use capabilities as quickly as possible.

Administrative, Regulatory and Industrial Implementation

Achieving these operational and tactical ambitions requires more than just strategy and technology – it hinges on effective administrative, regulatory and industrial instruments. NATO, the EU and national authorities have each mobilized a suite of tools to turn strategic intent into concrete programs, rules and incentives that drive progress on maritime security and undersea infrastructure protection. The implementation can be thought of on several levels: policy and legislation, funding and procurement mechanisms, institutional coordination frameworks, and industrial policy initiatives. Together, these set the “rules of the game” for how companies, research bodies and militaries develop and field the needed capabilities.

At NATO’s level, the primary vehicle is the NATO Defence Planning Process (NDPP) and associated capability targets. Through NDPP, Alliance planners have introduced specific targets for member nations related to this priority – for example, targets for number of ASW-capable frigates, deployable MPA squadrons, or national capabilities to protect critical infrastructure[78]. These targets, agreed by all Allies, effectively commit each country to fill certain portions of the overall capability gap. NATO’s planning documents post-2022 explicitly identify critical undersea infrastructure protection as a requirement within the collective defence domain, ensuring that national defence plans take it into account. NATO has also stood up coordination structures to implement the priority. Beyond the Maritime CUI Centre at MARCOM, a high-level NATO Coordinator for Critical Infrastructure Resilience (within the International Staff) liaises with member states on progress and gaps[40][79]. This role involves facilitating exercises, sharing best practices, and pushing forward Alliance-wide initiatives like the new undersea infrastructure Incident Reporting Cell, which simplifies how Allies report and receive warnings about undersea incidents. In terms of procurement, NATO itself does not buy big hardware (that’s up to nations), but it has expanded common funding for relevant enablers – such as funding for joint research through the NATO Science & Technology Organization on underwater drones, or upgrades to NATO Communications and Information Agency systems to better handle maritime data. Notably, NATO’s emerging innovation bodies are being tapped: the NATO Innovation Fund, a €1 billion multi-nation venture capital fund launched in 2023, listed “autonomous systems, energy and sensor tech” among its priorities, which directly encompasses undersea surveillance drones and power systems. Likewise, the DIANA (Defence Innovation Accelerator for the North Atlantic) initiative is soliciting proposals from start-ups working on maritime situational awareness, maritime IoT sensors, and other dual-use tech that could aid this mission. These NATO-level instruments aim to accelerate the pipeline of solutions from concept to prototype to deployment.

On the European Union side, a rich tapestry of legislation, regulations and funding programmes has been deployed. First, in the legal realm, the EU updated its regulatory baseline for critical infrastructure protection. The Critical Entities Resilience (CER) Directive (EU 2022/2557), adopted in late 2022, establishes binding requirements for EU member states and operators to protect critical infrastructure across sectors, including energy and digital infrastructure[41][42]. Under this law, operators of essential services (for example, a telecom company owning a major undersea cable, or an energy firm running an offshore pipeline) must conduct risk assessments and implement resilience measures; governments must have national strategies for protecting such infrastructure. While the directive doesn’t single out subsea cables by name, they fall under “digital infrastructure” and “energy” sectors, and the post-Nord Stream political context makes clear that subsea assets are a priority concern[13][11]. The EU also enacted the Network and Information Security Directive (NIS2) in 2022, which covers digital infrastructure and imposes cybersecurity obligations – relevant since a cyberattack could be used to disrupt undersea cable control systems or monitoring. These regulations effectively force better preparation: a cable operator in, say, France now must have contingency plans for outages and share information on incidents with authorities, creating more transparency and readiness in the system.

The EU’s funding instruments have been especially significant in jump-starting capability development. The European Defence Fund (EDF), launched in 2021, specifically earmarks funding for collaborative R&D projects that address critical capability gaps identified by member states. Recognizing the undersea threat, the EDF’s 2023 and 2024 work programmes included topics on “Underwater Warfare” and “critical seabed infrastructure protection.” One call (EDF-2023-DA-UWW-ASW) allocated around €90 million for next-generation ASW solutions[80], and another research call (EDF-2025 “Great depth enabling technologies”) focuses on deep-water defence tech to protect infrastructure down to abyssal depths[65][70]. These EDF projects bring together industry, SMEs and research institutes from multiple countries – for example, the aforementioned SEACURE program led by Thales involves 35 partners across 13 nations and is co-funded by the EDF to deliver an integrated system for autonomous ASW and infrastructure protection by 2028[81][82]. The EDF requires that participants be from EU (or associated) countries and that intellectual property is retained in Europe, aligning with the EU’s push for strategic autonomy. This effectively filters which companies and technologies are supported – favoring European-developed solutions and reducing reliance on non-allied suppliers. Indeed, projects like SEACURE build a European ecosystem of undersea defence tech, so that Allies are not solely dependent on US or others for things like drone swarms or advanced sonars[82][83]. Complementing the EDF, the EU’s Permanent Structured Cooperation (PESCO) framework allows groups of member states to launch joint projects. The Critical Seabed Infrastructure Protection (CSIP) PESCO project is one such example, led by Italy with participants including France, Greece, Spain, Portugal, Bulgaria and now Ireland[60][61]. By agreeing on common technical requirements and pooling resources, these nations aim to develop a shared undersea surveillance system more efficiently than if they acted alone. The EU has also leveraged civil funding for dual-use purposes: for instance, through the Connecting Europe Facility, it provided funds to improve the physical security of certain cross-border energy interconnectors and data hubs in 2023–24, which indirectly benefits undersea link resilience (e.g. improving landing station security for cables).

Another emergent instrument is the EU’s focus on standardisation and certification for novel defence technologies. For unmanned maritime systems, there is not yet a mature certification regime (e.g. how to certify an autonomous underwater vehicle to operate in civilian waters or alongside manned ships). The European Defence Agency (EDA) has task forces looking at standardising interfaces and safety standards for such systems, so that procurement and deployment can be streamlined across countries. This kind of administrative groundwork is less headline-grabbing but crucial – it means when NATO or a coalition wants to deploy a multinational team of underwater drones, those drones can technically and legally work together. Similarly, the EU and NATO are coordinating on exercises and training as implementation tools. A new EU-NATO “playbook” for responding to hybrid threats against infrastructure was developed in 2023, which lays out step-by-step how the two organizations coordinate if, say, multiple cables are cut one day[84][85]. This includes who notifies whom, how joint investigation teams might form, and how to engage the private sector (which owns much of the infrastructure). In essence, they are establishing procedural interoperability alongside technical interoperability.

National governments, for their part, have put forward procurement programmes and industrial policies aligned with this priority. Many allies have announced dedicated purchases or initiatives: the UK’s Royal Navy, for example, quickly moved to acquire two specialist Multi-Role Ocean Surveillance (MROS) ships after identifying the need to protect undersea cables. The first of these vessels, outfitted with undersea drones and submersibles, entered service in 2023[86][87]. Germany’s navy has initiated the procurement of seabed surveillance systems as part of a new “Marineunterstützung” (naval support) concept, and has directed funding to domestic firms for developing modular sensor pods that could be dropped from ships to listen for undersea activity. France’s government launched an “Ocean Protection Plan” in 2023 that, among other things, boosts support for companies making tethered underwater robots and calls for expanding the French Navy’s capabilities to monitor strategic undersea approaches to Europe (like cable landings in Brittany). In the Nordic region, Norway – heavily reliant on energy pipelines – has pressed ahead with a national program to harden offshore platforms and set up rapid repair agreements; the Norwegian Navy has also leased additional research vessels that can be purposed for undersea surveillance, effectively enlarging their fleet on short notice. These national measures are increasingly coordinated: in 2022, Germany and Norway spearheaded a joint proposal within NATO to divide responsibility for undersea infrastructure protection by regions, offering that countries provide “framework nations” for hubs (Norway for the High North, Germany for the Baltic, etc.)[88][89]. This has administrative implications – those lead nations align their procurement (e.g. Norway focusing on Arctic-capable autonomous vehicles, Germany on shallow-water sensors for the Baltic) and partner with neighbors to fill gaps. It’s a blend of NATO coordination with national execution.

Administrative implementation also involves the nitty-gritty of bureaucratic coordination and legal authority domestically. Many countries had to adjust laws to enable their militaries to operate more freely in protecting civilian infrastructure. For instance, Sweden and Finland, upon joining NATO, conducted reviews of how their armed forces can intervene to protect foreign-owned cables or pipelines in their Exclusive Economic Zones – clarifying rules for use of force in peacetime if a sabotage is suspected. The UK, as noted, adjusted its rules of engagement at sea to allow more robust action (including boarding or impounding suspect vessels) under Operation Atlantic Bastion[21][90]. These legal tweaks are an important implementation aspect: they translate political will into authorized action on the ground (or rather, on the water). Similarly, countries have signed new Memoranda of Understanding (MOUs) with industry, for example agreeing on information-sharing protocols so that if a telecom company sees a drop in a cable’s signal integrity, they immediately inform the navy for investigation. The EU has encouraged such public-private coordination through its recommendations, and NATO’s CUI Network actively involves industry reps to shape best practices[40][29].

Industrial policy tools are also being wielded to address supply chain and production aspects of this priority. Recognising that some critical components are sourced from outside allies, the EU and national governments have begun incentivising domestic production. The EU’s new Chip Act (2023) aims to boost European semiconductor manufacturing – indirectly relevant because advanced semiconductors are vital in military sonar, signal processing, and encryption gear used in undersea security systems. Likewise, the proposed Critical Raw Materials Act will support supply chains for materials like rare earth magnets used in undersea sensors and motors, reducing dependency on Chinese sources. By tying eligibility for EDF funding to European supply chains, the EU is effectively steering companies to ensure key subsystems (like acoustic transducers or underwater communication modems) are developed within Europe[76][77]. NATO, for its part, has spotlighted the need to “eliminate defence trade barriers among Allies” in its 2025 Maritime Strategy, urging nations to simplify cross-border procurement and bolster the transatlantic defence industrial base for maritime needs[78]. Practically, this could mean harmonising export control rules so that, for example, a U.S.-made component in a UK undersea drone does not prevent it from being shared with a Baltic ally due to ITAR restrictions. It is a work in progress, but the direction is toward greater self-sufficiency and interoperability in production.

Finally, implementation comes down to money on the table. Funding intensity for this priority has been significant. At NATO’s 2023 Vilnius summit, several nations announced increased contributions: for instance, a consortium of allies is establishing a NATO Voluntary Fund for Infrastructure Resilience to finance items like deployable cable repair kits and shared stocks of sensors. The EU through EDF has committed well over €100 million specifically to undersea defence projects in the current budget cycle[80][91]. Individual nations have earmarked substantial budgets as well (the UK’s MROS ships are part of a £2bn naval investment, Norway’s defence plan 2024–2028 allocates new funding to “maritime surveillance and seabed warfare capabilities”). Moreover, the EU’s emergency support instrument was used in late 2022 to fund immediate measures like aerial surveillance flights over the North Sea after Nord Stream, showing flexibility to divert funds swiftly for this cause. The new ASAP (Act in Support of Ammunition Production) initiative by the EU, while focused on munitions, underscores a broader trend of Brussels directly funding defence-industrial ramp-ups – a model that could conceivably be applied to maritime kit if needed, ensuring factories can meet sudden demand surges (for example, if many sonar arrays need producing in a crisis).

In sum, the implementation of “Maritime Security & Undersea Infrastructure Protection” is characterized by a dense web of policy mandates, cooperative frameworks, and targeted investments. Through directives and standards, the EU compels stakeholders to plan and act; through funding and PESCO, it nurtures the required technologies and capacities; NATO sets goals and facilitates coordination; nations enact laws and spend money to acquire assets. All these instruments align to filter and shape the marketplace of ideas and products: companies know that European funding favors solutions that improve autonomy from external suppliers, researchers see priority calls for seabed tech, investors see governments willing to back projects in this niche, and military end-users get clarity on what capabilities they can count on and under what rules they’ll operate. It is a massive, concerted administrative effort to ensure that lofty strategic goals are translated into practical deliverables – from a new drone in the water, to a new memorandum on intel-sharing, to a new factory line for fiber sensors – within the allied democracies’ defence-technological ecosystem.

Structural Bottlenecks and Strategic Dependencies

Despite the momentum, serious bottlenecks – industrial, technological, regulatory and financial – complicate the full implementation of this priority. These structural constraints risk slowing the deployment of needed capabilities and could leave critical vulnerabilities unless mitigated. Identifying and addressing them has become part of the strategic calculus, as Allied nations realise that weaknesses in the “security of supply” or industrial base can undermine deterrence just as surely as gaps in force posture.

Industrial bottlenecks are among the most immediate challenges. The surge in demand for ASW and undersea surveillance assets is running up against limited production capacity and long lead times. For example, the handful of Western companies that produce advanced sonar systems (such as Thales, Atlas Elektronik, Raytheon) have order books stretching out years. Ramping up production of complex towed sonar arrays or dipping sonars is not trivial – it requires specialised components (like piezoelectric ceramics and transducers) and skilled labor. Similarly, building new maritime patrol aircraft or warships with ASW fit can take the better part of a decade from design to delivery. As NATO parliamentarians lamented, Allies allowed their ASW industrial base to shrink after the Cold War, and rebuilding it is neither cheap nor fast[72][73]. One concrete bottleneck is the limited number of shipyards and manufacturers for certain platforms. For instance, only a few yards in Europe can build submarines or large surface combatants, and most are already busy with existing orders (e.g. the German and Norwegian navies’ new Type-212CD submarines will occupy TKMS shipyard well into late 2020s). This means any newly agreed NATO requirement for more ASW frigates or subs cannot be met quickly – there is a multi-year queue. Even the production of unmanned systems faces constraints: manufacturers of specialized UUVs and USVs (often medium-sized tech firms) can struggle to scale up. If Allied navies tomorrow each wanted dozens of autonomous underwater drones, the current industry might not keep pace without significant expansion.

Supply chain dependencies further aggravate industrial bottlenecks. Many high-tech components used in undersea warfare systems come from outside the Alliance. A notable dependency is on rare earth elements and specialized magnets for sonar and electric propulsion systems. These materials (like Neodymium-Iron-Boron magnets) are predominantly sourced from or processed in China. Allies worry that in a crisis, China (a “systemic rival” as per NATO) could restrict exports, crippling production or maintenance of critical sensors[92]. While efforts are underway to diversify sources – for example, developing rare earth supply in Europe or allied countries – this is a medium-term fix at best. In the short term, stockpiling and finding substitute materials are the main options. Another dependency is in microelectronics and semiconductors. Advanced signal processors, FPGAs and other chips in military systems often come from global supply chains centered in East Asia (Taiwan, South Korea, etc.). The EU Chip Act and allied initiatives aim to localize more of this production, but currently a naval drone or sonar might contain many parts that have no on-shore manufacturing alternative. If geopolitical tensions escalate, shortages of these could delay equipping new systems or keeping existing ones operational[93]. Additionally, some Allies rely on non-European suppliers for key platforms – for instance, nine European NATO countries have purchased American P-8A Poseidons for maritime patrol. While the U.S. is a trusted ally, this creates a form of single-source dependency: maintenance, spare parts and upgrades for those aircraft depend on Boeing and the U.S. supply chain. If the U.S. were preoccupied or if export rules change, it could impact availability. European states have discussed launching a collective program for a next-generation MPA (the abandoned MAWS project), partly to avoid over-reliance on U.S. exports, but that is on hold. Thus in the near term, the reliance on the U.S. for certain high-end capabilities (MPAs, some drones, anti-sub weapons) remains a strategic dependency – manageable, but a dependency nonetheless.

Technological bottlenecks also present hard limits. By physics and nature, the undersea domain is tough to monitor and control. Even the best technology struggles with basic challenges: saltwater attenuates electromagnetic signals, meaning underwater communications and sensing are mostly limited to sound, which travels slower and with less clarity than radio. This imposes a communications bottleneck – underwater drones, for instance, can’t send high-bandwidth data back in real time unless they surface to use satellite links. That complicates continuous surveillance, as either the drone must periodically surface (creating potential gaps or risk of detection) or it operates blind and stores data. Efforts to develop high-bandwidth underwater communications (optical or acoustic modems) are making progress but not yet at levels comparable to above-water networks. Another tech bottleneck is battery energy density for autonomous systems. Endurance of UUVs is often measured in hours to a few days. To truly patrol long pipeline stretches or loiter for weeks, leaps in battery tech or alternate power (like small fuel cells or ocean thermal energy) are needed. Until that happens, covering large areas demands many vehicles or frequent swaps, which is resource-intensive. Detection capability itself has limits: quiet diesel-electric submarines or UUVs operating near the seabed are very difficult to detect with passive sonar due to clutter and ambient noise. While new active sonar techniques (like low-frequency active sonar) can improve detection, they come with trade-offs (they reveal the searcher’s presence and may harm marine life). There is also the risk of a cat-and-mouse countermeasure spiral: as Allies deploy underwater sensors and drones, adversaries can develop countermeasures like sonar jammers, decoys, or stealthier drones. For example, advances in coatings and morphing designs could make enemy UUVs even less visible to acoustic sensors[62][94]. Thus, technologically, Allies are chasing a moving target. Certain emerging threats don’t yet have reliable counters – e.g., if an adversary simply deploys a dozen cheap free-floating mines or explosives near infrastructure, differentiating those from harmless debris is extremely tough. This highlights an analytic bottleneck: the difficulty of attribution and discrimination undersea. Knowing something happened (e.g. a cable was cut) is easier than knowing who or what did it. Lack of persistent video or human presence underwater means forensic evidence is hard to come by. This complicates deterrence – if Allies cannot confidently attribute an attack, they cannot easily punish it. In summary, technology is improving but hasn’t erased the fundamental harshness and opacity of the undersea environment.

Regulatory and administrative bottlenecks also impede progress. One issue is that undersea infrastructure protection straddles civilian and military responsibilities, and coordinating between them can be slow or inefficient. While NATO and the EU have frameworks, on the ground it often requires case-by-case arrangements. For example, legally, navies may not be able to act in another nation’s waters without permission, even if a threat is detected just across a boundary. Getting timely clearances is a bureaucratic hurdle. The 2024 Finland-Estonia pipeline incident illustrated this: when a pipeline between the two was damaged, both nations and NATO were involved in investigating, but formal procedures had to be navigated for sharing evidence and possibly deploying assets in each other’s zones[4][95]. Another administrative friction is in procurement: multi-national projects, while beneficial, often encounter bureaucratic delay due to differing national requirements, contracting rules, or budget cycles. PESCO projects, for instance, have seen slower progress at times because participants need to align funding and specifications. Even on the NATO side, common-funded projects (like installing a new network of seabed sensors as a NATO asset) can be bogged down in committee debates over cost shares and management. Bureaucratic inertia can also hamper innovation adoption – militaries have lengthy testing and evaluation pipelines before fielding new tech, which might be at odds with the urgency of the threat. A small startup might have a great sensor, but getting it certified for use in an Alliance operation could take years, by which time the startup might wither without contracts. Moreover, the classification of many activities creates silos: much of undersea protection falls under secret intelligence or military ops, meaning that even within governments, the information might not be widely shared with other agencies that need it (like environment or energy departments). This can delay comprehensive responses or investments.

Financial bottlenecks cannot be ignored either. While funding has increased, resources are still finite and trade-offs acute. The push to strengthen undersea protection comes at the same time Allies are trying to invest in many other priority areas (from air and missile defence to land forces and munitions replenishment after aiding Ukraine). Every new frigate or MPA for ASW competes with other defence budget items. Some countries, especially smaller allies, face affordability issues – they rely on collective measures because they cannot independently field all needed capabilities. For example, Baltic states have almost no navy to speak of, so they depend on larger allies to provide naval security; if those larger allies face budget pressure, maritime coverage in that region could suffer. Another financial aspect is the private sector’s capacity and willingness to invest in resilience. Many subsea cables are owned by consortia of private telecom companies or even Big Tech firms; pipelines by energy companies. These actors operate on commercial logic and may not invest in expensive security improvements unless required or subsidised. Laying a backup cable or installing sensors along a pipeline can be costly, and companies might prefer to externalize that cost to navies or insurers. Governments have begun mandating certain measures (via CER Directive or national laws), but enforcement and verifying compliance is resource-intensive for regulators. Insurance is a related bottleneck: after Nord Stream, insurers have reportedly reassessed premiums for undersea infrastructure. If insurance becomes very costly or limited for these risks, it could impact projects like new offshore wind farms or cables – possibly slowing their deployment or making governments step in as insurer of last resort.

All these bottlenecks create potential vulnerabilities in deterrence and readiness. Industrial lags mean that if a crisis erupted in the short term, NATO might still lack optimal resources to respond – adversaries are surely aware that some Allied maritime patrol squadrons or drones are “on the way” but not yet in hand. Technological and regulatory gaps could mean that an enemy finds seams to exploit: for instance, using civilian cover or legal grey zones to carry out an attack that Allies cannot attribute or react to quickly, thereby sowing confusion and doubt. Dependencies on external suppliers (even friendly ones) introduce uncertainty: what if a geopolitical event in Asia restricts the flow of semiconductors just when Europe is trying to produce an urgent batch of sensors or spare parts to replace sabotaged ones? Such a scenario is not far-fetched and would directly undermine the resilience of Allied responses. Dependencies on single nodes – e.g., one repair ship – are also worrisome. The global fleet of cable repair vessels is limited; if multiple cables were cut in different places around the same time, there simply aren’t enough ships and crews to fix them quickly[96][97]. Adversaries could exploit this by coordinated sabotage, knowing the bottleneck in repair capacity will maximize outage duration. This has driven NATO and EU to consider how to surge repair capabilities, perhaps by having naval ships or commercial vessels retrofitted as emergency cable layers, but that is still conceptual. In essence, bottlenecks and dependencies present a risk that despite best efforts, an agile adversary might strike where Allied defences are thinnest or slowest.

Identifying the most critical dependencies is an ongoing task. European officials frequently cite the dependency on non-allied undersea infrastructure manufacturers – for example, concerns were raised about a Chinese company (HMN Tech) that had been involved in laying some cables in Europe[98][99]. Moves to exclude such companies from future projects are part of reducing strategic dependence (akin to how Huawei was excluded from 5G networks). In defence terms, dependence on US technology is both a strength and a vulnerability: American capabilities like maritime surveillance planes or satellite intel are unparalleled and strengthen deterrence, but if Europe cannot act independently in their absence, that’s a strategic limitation. The EU-NATO Task Force report of 2023 pointed out that deeper cooperation is needed precisely to manage such interdependencies and ensure collective resilience[43][44]. This includes stockpiling critical spares and developing interchangeability (for instance, making sure a French or Japanese made sonar buoy could substitute for an American one if needed).

In summary, the path to securing Allied undersea infrastructure is partially blocked by chokepoints in industry and technology and by entanglements of global supply and regulation. These bottlenecks are now themselves the focus of policy: NATO and EU meetings frequently include discussions on supply chain security, industrial ramp-up and fast-tracking innovation. Overcoming them is recognized as vital to credibly sustain the priority. Until they are overcome, however, they constitute a form of strategic vulnerability – one that sophisticated adversaries are likely to probe. The Allied response has been to shine light on these dark corners: map out exactly where the dependencies lie, work with private sector to alleviate them, invest in redundancy (multiple suppliers, multiple sensors) and exercise fallback procedures (like what to do if a key component is unavailable). The very existence of these efforts indicates that Allies understand a blunt truth: no matter how strong our navies and strategies, weak links in supply or inertia in bureaucracy can undermine our security. Thus, strengthening those links is part and parcel of the maritime security priority.

Implications for Companies, Technologies, Research and Capital

The strategic priority of protecting maritime security and undersea infrastructure reverberates far beyond navies and ministries. It is fundamentally reshaping the opportunity landscape for companies, research institutions, and investors in the defence-tech ecosystem of allied democracies. As governments pour attention and resources into this domain, certain industries and technologies are being elevated, new collaborations with academia are forming, and capital is being steered towards relevant innovation. Ultimately, this priority serves as a bridge connecting institutional demand with the private sector and scientific community – aligning them toward common goals of capability development and deployment.

Defence and technology companies of various sizes stand to play pivotal roles. Large prime contractors – the traditional giants of the defence industry – are central players because they have the breadth and systems integration ability to deliver complex maritime solutions. Firms like Thales, BAE Systems, Lockheed Martin, Naval Group, Saab, and Atlas Elektronik are deeply involved in undersea warfare programs. They are leveraging increased funding to accelerate product development: for instance, Thales not only leads the EDF-funded SEACURE project for autonomous ASW systems[81][82], but is also investing in its own research on next-gen sonar processing and unmanned vehicles, expecting strong future demand. These primes act as integrators, bringing together sensors, platforms, AI and weapons into cohesive systems for navies. However, they rely on a network of mid-tier suppliers and specialised SMEs who provide critical subsystems and innovations. The priority on UUV/UAV surveillance has opened space for specialized robotics companies – often smaller, highly innovative firms. For example, Kongsberg Maritime (Norway) and ECA Group (France) are mid-sized companies that specialize in autonomous underwater vehicles and mine countermeasure drones; they now find their markets expanding from minesweeping into broader infrastructure monitoring. Companies making niche products like fiber-optic acoustic sensors (e.g. France’s iXblue, now part of Exail, or smaller startups spun from university labs) suddenly see a path to scale up via defence contracts[68][100]. Even companies outside traditional defence are getting involved: telecom firms like Nokia or SubCom have expertise in undersea cables and are exploring offering “security packages” for those cables, partnering with defence firms to integrate warning sensors or access points for navies. This indicates a blending of civilian and defence sectors, guided by the priority’s demands.

We can categorize companies in this ecosystem by how they align with capability segments. Prime contractors (e.g. Naval Group, BAE) will likely lead on delivering platforms – warships, submarines, and integrated systems like complete surveillance networks – and also act as lead system integrators for consortium projects. Mid-caps and specialized SMEs will contribute enabling technologies: these include underwater drones (Exail Robotics, Saab’s underwater systems division, etc.), advanced sonar and signal processing units (Germany’s Atlas Elektronik, Italy’s Leonardo in sonar), anti-submarine weapons (e.g. light torpedoes by Italy’s Whitehead Sistemi Subacquei). Deep-tech startups are increasingly entering with disruptive solutions: for example, startups in the AI realm offering pattern-recognition algorithms for sonar feeds, or those in the energy sector developing novel battery tech suitable for long-endurance UUVs. NATO and national innovation hubs have been actively scouting such startups to involve them through challenges and accelerators (DIANA ran a challenge in 2024 on “deep ocean surveillance” which attracted startups with ideas like swarms of inexpensive sensors or bio-mimetic drones). These smaller actors are enabled by the trend of modularity – primes are designing systems to be modular so that, say, a new sensor payload from a startup can be plugged into an existing drone framework relatively easily, speeding adoption.

The priority also delineates which technological clusters are most valued. Broadly, maritime robotics and autonomous systems have become a hot cluster. Companies in this space – whether making autonomous underwater gliders, unmanned surface surveillance craft, or aerial drones optimized for maritime patrol – see high interest from navies and coast guards. The European industry, for example, through PESCO projects like MUS (Maritime Unmanned Systems) and in NATO’s Maritime Unmanned Systems Initiative (MUSI), is coalescing a cluster of firms and labs dedicated to unmanned maritime tech[101][102]. Another cluster is sensors and sensing networks: this includes traditional sonar makers but also newcomers in fiber optics, satellite oceanography, and multi-static sensor networks. With EU funding, collaborative networks between sensor manufacturers and telecom companies are forming – e.g., a project where a sensor SME works with a cable operator to retrofit a live cable with sensing capability. Cybersecurity and communication tech companies also have a niche: ensuring the security of data links to unmanned systems or the hardening of offshore SCADA systems is an area where firms like Palo Alto Networks (cyber) or Ericsson (with secure 5G at sea concepts) might contribute solutions. Even energy and propulsion companies get involved insofar as power systems for remote sensors or vehicles are needed – we see, for instance, companies like Saft and Siemens developing high-capacity pressure-tolerant batteries and underwater power management, anticipating large orders as underwater drones proliferate.

For research organizations, the undersea protection push directs attention and grants to certain fields. Universities with strong ocean engineering, robotics, acoustics, and materials departments are highly relevant. We see increasing academic involvement: the KTH Royal Institute of Technology (Sweden) is a partner in SEACURE[103][83], providing its expertise in autonomous systems and cooperative control algorithms. In Italy, the University of Rome’s spinoff WASS contributed to the SCUALE project on materials for sonar, leveraging academic material science labs[68]. Many nations’ public research institutes, like France’s IFREMER (traditionally focused on oceanographic research) or Norway’s FFI (defence research establishment), have expanded programs on “maritime security”. FFI, for example, is developing prototypes of seabed sensors and exploring non-acoustic detection methods, directly aligning with NATO’s needs[104][105]. European research infrastructures like large test ranges and simulation facilities are also key: Norway’s Størfjorden and Italy’s NATO CMRE in La Spezia provide environments to test new drones and sensors – the CMRE has been conducting yearly experimentation exercises where companies and scientists jointly trial swarms of underwater robots in detecting targets. The EU encourages such use of shared facilities so that more actors can refine their tech. Additionally, specialized forums like the NATO STO’s panels (e.g., the Centre for Maritime Research & Experimentation’s scientific conferences) are fostering knowledge exchange. In academia, we also see a multi-disciplinary approach emerging – combining oceanography (to understand how sound propagates or how currents might move a rogue mine) with AI (to interpret data) and even law/policy (naval war college programs examining legal rules for infrastructure protection). This priority pulls these threads together by providing concrete problems to solve. For example, a consortium of universities and small companies might come together to answer an EDF call about deep-sea surveillance enabling tech: one university handles novel materials for deep pressure, another does AI for signal processing, a company provides the prototype hardware, etc. Such collaborations have proliferated under EU programmes, directly guided by the priority’s objectives[52][71].

From the perspective of capital and investors, maritime security used to be a niche, but it is now seen as a growth area with relatively assured government backing. Different types of capital are engaging. Sovereign wealth funds and public investment banks have shown interest in bolstering domestic industries in this space as part of strategic security of supply. For instance, France’s public investment bank Bpifrance, through its DefInvest fund, has invested in a French startup specializing in underwater robotics, effectively betting on its role in national and European defence programs. The European Investment Bank (EIB), historically cautious about defence, has signaled openness to dual-use projects that enhance infrastructure resilience – one could envision EIB loans or guarantees for a project to harden an international subsea cable with new tech, as it falls under infrastructure protection. EU financial instruments like the European Innovation Council (EIC) are also relevant: the EIC’s accelerator has funded dual-use tech startups (some working on robotics or sensors that have maritime security applications), granting them equity and support to scale. The newly established European Defence Industry Reinforcement through common Procurement (EDIRPA) and the proposed European Defence Investment Programme (EDIP) aim to facilitate joint procurement – if, say, a group of countries decide to collectively buy a fleet of anti-submarine drones, these instruments could provide EU co-financing, reducing risk for both industry and state buyers.

In the private finance sphere, defence-focused venture capital has begun to include the maritime/autonomy sector in its portfolio. Funds such as Anduril’s venture arm in the US and Europe’s Hoxton Ventures (which has invested in defence tech startups) are looking at companies providing novel maritime solutions, encouraged by assured government interest. The creation of NATO’s own venture fund signals to private investors that defence innovation – including underwater tech – is a worthwhile bet, with NATO potentially co-investing or at least providing a validation stamp. Private equity is also active in the industrial base: we have seen PE firms acquiring small but critical marine tech companies with the expectation that their value will rise as contracts flow. However, investors also keep an eye on regulatory risk: much of this sector is subject to export controls and government oversight (some nations restrict foreign ownership of companies making sensitive undersea tech). This has sometimes led to strategic domestic capital being favored – e.g., German and French governments quietly signaled in 2023 that key undersea cable sensor providers should remain under friendly ownership, deterring outside buyouts.

One notable dynamic is corporate strategic investment – large defence primes or even non-defence multinationals investing in startups or smaller firms to secure a technological edge. For example, a big naval shipbuilder might invest in a startup that makes a novel AUV, integrating that tech into its future offerings. Likewise, telecom companies might invest in cybersecurity firms specializing in undersea cable control systems to protect their assets. These cross-industry partnerships are spurred by the clear articulation of needs in public documents; when NATO says it needs capabilities X and Y by a certain date, it creates a market signal.

As a result of these developments, we observe an ecosystem convergence: political authorities define the mission and desired capabilities; companies respond by developing solutions; researchers feed innovation into those solutions; and investors supply capital to scale the promising ideas. A tangible example is the rapid progress in Nordic-European cooperation: after pipeline incidents, Norwegian and Finnish firms, backed by government and sometimes venture funding, started trials of using autonomous drones to continuously patrol pipelines. Their success could lead to contracts, which then attract more investors seeing that as a replicable service for other regions.

Looking ahead, this priority is expected to evolve the relationships between these actors. Governments and alliances will likely take a more hands-on approach in orchestrating consortia (picking “national champions” or mandating collaborations to ensure both large and small players benefit and that key knowledge stays onshore). Companies that traditionally focused on civilian maritime industries (like offshore oil servicing or undersea cable laying) may increasingly branch into security services, effectively becoming defence contractors in their niche – e.g., offering monitoring-as-a-service to governments for stretches of seabed. Research entities might see more direct funding lines from defence budgets (NATO’s Science for Peace and Security Programme, for example, has sponsored a project on novel sensors involving universities[79]). And the flow of capital will probably tilt more toward dual-use innovations that can address this and adjacent priorities (like space-based maritime surveillance, or AI for multi-domain awareness).

For investors, one attractive element is that this priority is long-term and steady. Unlike some urgent needs that might fade if a war ends, protecting critical infrastructure is viewed as a permanent necessity in the face of enduring strategic competition. The time horizon of, say, 2025–2035 is filled with planned programs (replacing aging frigates with ones optimized for ASW, deploying undersea sensor networks, etc.), giving industry and investors a clear runway. Additionally, there’s potential for the civilian spin-offs of military technology: improvements in undersea autonomous navigation or fiber sensing can benefit commercial domains like deep-sea mining, scientific oceanography, or offshore wind maintenance – markets which investors can also tap, enlarging the pie. Allied governments encourage this dual-use synergy as it lowers costs and builds broader support (for instance, the EU touts that better undersea awareness helps detect environmental hazards and illegal fishing, not just military threats[106][107]).

In conclusion, the maritime security and undersea infrastructure protection priority has moved from being a narrow military concern to an organizing principle for a wide community of enterprises, researchers and financiers. It dictates which companies will be at the core (those providing underwater vehicles, sensors, ASW platforms), which will enable (AI firms, communication providers), and which may remain peripheral (some legacy defence contractors focused on land systems might find less relevance here). It draws in universities and labs to tackle cutting-edge questions, often with direct line-of-sight to application. And it signals to capital markets that there is a substantial, sustained demand for innovation in this field – with public funding available, reduced market risk due to government guarantees, and potential civil crossover. All these actors – industry, academia, investors, along with the defence institutions – are being knitted into a cohesive innovation and production network driven by the priority. The result, if successful, will be not only enhanced security for allied undersea infrastructure but also a strengthened transatlantic defence-industrial base, technological leadership in a critical domain, and new growth opportunities rooted in making the world’s oceans safer for the democracies that depend on them.

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List of Sources

NATO and Allied Strategy & Doctrine – NATO Strategic Concept 2022 (Madrid, June 2022) emphasizes maritime security as key to peace, committing Allies to defend against all threats in the maritime domain and protect vital undersea lines of communication[6]. The updated NATO Alliance Maritime Strategy (2025) underscores securing undersea infrastructure as a core task for Allied maritime power[15][16] and outlines measures like increased situational awareness with emerging tech[45][108]. In NATO Parliamentary Assembly deliberations, lawmakers warned of dangerously atrophied ASW capabilities and urged investment in new sensors and unmanned vehicles[72][58], noting the threat to undersea cables[10]. The Vilnius Summit Communiqué (2023) directed creation of a NATO Maritime Centre for Undersea Infrastructure Security[14], and NATO’s Deputy Secretary General announced the launch of “Baltic Sentry” in 2025 to bolster presence in the Baltic Sea, integrating frigates, maritime patrol aircraft and drones to protect undersea assets[36][33]. The UK’s National Security Strategy 2025 highlights the nation’s dependence on subsea cables (99% of digital data) and gas pipelines, assigning the Royal Navy to lead in securing undersea infrastructure via Operation Atlantic Bastion and allied task forces[7][109].

European Union Policies and Initiatives – The EU’s Maritime Security Strategy (revised 2023) and Council conclusions label protection of maritime critical infrastructure (pipelines, internet cables, offshore wind) as a top priority[13], calling for regional surveillance plans, innovative tech and unmanned monitoring systems to improve resilience[19]. Following Nord Stream, the EU and NATO established a Joint Task Force on Resilience of Critical Infrastructure; their Final Report (June 2023) recommends deeper NATO-EU cooperation, information sharing, alternate transport routes and joint research to strengthen infrastructure resilience[41][42]. The EU’s Critical Entities Resilience Directive (2022) and NIS2 impose obligations on states and operators to assess risks and protect critical energy and digital infrastructure[43][44]. EU funding mechanisms have mobilized substantial support: the European Defence Fund 2023 call allocated €90M to underwater warfare capabilities[80], and the EDF 2024 programme launched the SEACURE project (35 partners, 13 countries) to develop an autonomous system-of-systems for ASW and seabed infrastructure protection by 2028[81][82]. Additionally, a PESCO project on Critical Seabed Infrastructure Protection was initiated in 2023 with seven EU nations collaborating to improve underwater surveillance assets[60][61].

Regional and National Developments – Norway and Germany’s joint initiative (2024) proposed regional NATO hubs for undersea infrastructure monitoring (Norway offering a High North hub, Germany for the Baltic), to leverage national expertise for Alliance-wide benefit[88][89]. This builds on NATO’s establishment of a Maritime CUI coordination cell at MARCOM in early 2024[38]. In the North Sea and North Atlantic, NATO navies increased patrols after unexplained damage to cables and the Baltic Connector gas pipeline in 2023[4][95]. The Nordic Joint Expeditionary Force (JEF) and UK have been actively tracking Russia’s “shadow fleet” vessels near subsea infrastructure[49]. Ireland’s 2024 Defence Review, despite traditional neutrality, prioritised maritime security and decided to acquire naval radar/sonar for undersea monitoring; Ireland also joined the Italian-led PESCO project on seabed infrastructure protection[110][60], reflecting the strategic importance of the Atlantic subsea cable nexus off its coast[96][111].

Technological and Industrial Responses – NATO’s Alliance Maritime Strategy calls for Allies to develop and deploy new technologies for surveillance and tracking of maritime threats, synchronized with civilian stakeholders[35]. The EU Commission highlights innovations like fiber-optic hydrophone arrays enabling real-time, wide-area subsea monitoring – EDF projects CASSATA and SCUALE push these advances[67][68] – and frames the EU as an innovation leader in maritime security tech[112]. Corporate initiatives mirror this: Thales’ press release on SEACURE (Dec 2024) notes it builds on a prior EDIDP project (SEANICE) and aims at a European autonomous ASW and seabed warfare capability, integrating air, surface and underwater drones to detect and track underwater threats and protect infrastructure[81][82]. NATO Parliamentary reports stress harnessing new autonomous systems, AI and “360° sensor fusion” to counter undersea threats[58][59]. RAND research (2025) likewise observes that proliferation of UUVs and cyber capabilities is a “double-edged sword,” improving monitoring but also adversary attack options, and urges coordination and technological prioritization among Allies[62][94].

Exercises, Operations and Enforcement – NATO’s Dynamic Mongoose 2024 exercise in the North Atlantic practiced intensive ASW and protection of sea lines[75]. NATO officials emphasize multi-domain enforcement: at the 2025 Baltic Sea Summit, the NATO Secretary General lauded Finland’s firm legal action against suspicious vessels, warning that threats to infrastructure “will have consequences” such as boarding or impounding ships[12][90]. To enhance readiness, NATO launched the Critical Undersea Infrastructure Network with industry in 2024 to share threat intelligence and best practices[40][29]. The EU announced in 2023 it will hold annual maritime security exercises involving naval and coast guard assets to boost interoperability in addressing evolving threats, including hybrid attacks on infrastructure[47][54]. Together, these sources document how NATO, EU, and national authorities are implementing the maritime infrastructure protection priority through strategy, capability development, legal frameworks and on-the-water action.

Sources:

• NATO – Strategic Concept 2022. NATO Headquarters, Madrid Summit, June 29, 2022. (Para 23 on maritime security)[6]

• NATO – Alliance Maritime Strategy (AMS) (Official Text, 29 Oct 2025). NATO HQ. (Paras 4, 16 on protecting SLOCs and undersea infrastructure)[15][16]

• NATO – Alliance Maritime Strategy 2025 (Implementation). NATO Official Text (Paras 24–26 on tech, info-sharing, NDPP and industry cooperation)[35][78]

• NATO PA – Leona Alleslev, “Rebuilding NATO’s Anti-Submarine Warfare,” NATO Parliamentary Assembly Science & Technology Committee Report, Oct 2019. (Warnings on Russian subs, ASW shortfalls, unmanned integration, cable threat)[72][10]

• NATO PA – Nicholas Soames remarks on North Atlantic Security, NATO PA Defence & Security Committee, Oct 2019. (Need for robust maritime command, more MPAs, bases, infrastructure for reinforcements)[17][113]

• NATO – Vilnius Summit Communiqué, July 11, 2023. (Para on directing establishment of Maritime Centre for Critical Underwater Infrastructure Security at MARCOM)[14]

• NATO – NATO expands engagement on critical undersea infrastructure, NATO News, 21 Nov 2025. (CUI Network meeting in Rome; drones for surveillance; Italian Navy CUI Surveillance Center example)[40][29]

• NATO – Launch of “Baltic Sentry”, NATO News, 14 Jan 2025. (Regional Baltic Sea Allies Summit; NATO SG Mark Rutte announces Baltic Sentry to enhance presence and response; use of frigates, MPAs, naval drones; integrate national surveillance; CUI Network with industry; enforcement measures)[36][37]

• NATO – NATO & EU release Task Force Final Report on Resilience, NATO News, 29 June 2023. (Importance of resilience in energy, transport, digital infrastructure; recommendations for NATO-EU cooperation, info exchange, research)[41][42]

• EU – EU Maritime Security Strategy (EUMSS) – Council Conclusions, 24 Oct 2023. (EU policy: protecting maritime critical infrastructure top priority after Nord Stream; need innovative tech, regional surveillance, unmanned systems)[13][19]

• EU – Consilium: Maritime security, updated 2024. (EU commitments under Strategic Compass: naval ops, training, info-sharing; annual EU maritime exercise; Coordinated Maritime Presences; climate and maritime security; critical infrastructure focus, citing Nord Stream attacks and cable incidents; EU actions: develop tech, regional plans, unmanned systems for resilience)[114][115]

• EU – Critical Infrastructure and cyberattacks (Consilium site, 2023). (Emphasis that protecting maritime pipelines, cables, offshore wind farms is urgent; references to 2022 pipeline attacks, suspicious presence in North Sea, hybrid threats; EU measures to improve resilience)[115][116]

• EU Commission – Critical Infrastructure Protection & Resilience (CIPR) Newsroom, “EDF projects contribute to protection of Critical Maritime Infrastructure,” 23 Mar 2024. (Highlights EU focus on undersea infrastructure resilience; remote environments hinder monitoring/response; fiber-optic hydrophone tech via EDF projects CASSATA & SCUALE for covert multi-sensing and lead-free acoustic materials; real-time monitoring of wide areas with passive fiber sensors to safeguard subsea infrastructure)[67][68]

• EU Commission – EDF 2025 Call: Great-depth enabling technologies. (Call text outlining need for technologies for Seabed Warfare down to 6000m; motivated by sabotage on underwater infrastructures; calls for countering UUVs, protecting pipelines/cables; references PESCO, EDF, NATO projects already started; need for research on deep-water platforms, payloads, comms, weapons to defend critical subsea assets)[52][70]

• EU Defence – European Defence Fund 2023 call, EDF-2023-DA-UWW-ASW. (EU funding opportunity with ~€90M for next-gen underwater warfare solutions, showing EU’s commitment to ASW and undersea capabilities)[80]

• Thales Group – Press Release: “SEACURE – EU defence project led by Thales for underwater warfare”, 19 Dec 2024. (Details EDF-funded SEACURE programme: started Nov 2024, 45 months, 35 partners/13 countries; aims for European autonomous ASW & Seabed Warfare capability by 2028; focus on detecting, classifying, tracking underwater threats and protecting maritime infrastructure using air/surface/underwater drones; system-of-systems, modular, interoperable for collaborative combat)[81][82]

• High North News – Astri Edvardsen, “Norway Proposes a NATO Hub for Securing Critical Undersea Infrastructure in the High North”, 23 Oct 2024. (Germany & Norway joint statement to reinforce NATO role in CUI protection; launched NATO Maritime CUI Centre May 2023; proposing regional CUI hubs for North Sea, Atlantic, Baltic, Med, Black Sea provided by lead nations; Norway offers High North hub, Germany Baltic; hubs to monitor infrastructure, use national personnel/capabilities to detect and deter threats; context of Nord Stream 2022 and 2023 cable/pipeline damage in Baltic; quotes German DefMin Pistorius on hybrid attacks posing “considerable threat” to economy, comms, energy)[88][89]

• Defense News – Elisabeth Gosselin-Malo, “At Europe’s Atlantic edge, Ireland to focus on undersea monitoring”, Defense News (Europe), 30 Aug 2024. (Ireland’s 2024 Defence Review cites profound change in security; prioritizes maritime security; recommends acquiring naval radar & sonar for undersea monitoring; plans integrated air-land-sea monitoring; notes Ireland’s waters host crucial undersea comms cables – 97% global comms via cables, 3/4 of northern hemisphere cables near Irish waters – so sabotage would have huge impact; Ireland to develop sub-sea, littoral, critical infrastructure defence capabilities; working on new national maritime security strategy; joined Italian-led PESCO CSIP project in May 2023 to improve underwater surveillance with 7 EU states)[96][60]

• UK Government – National Security Strategy 2025: Security for the British People in a Dangerous World, published 2025. (Section on defending territory: UK as island relies on subsea cables for 99% digital comms and subsea pipelines for ~75% gas; territorial security “begins at sea”[7]; Royal Navy tasked to lead securing undersea infrastructure and maritime traffic – Operation Atlantic Bastion to counter Russian subs and “shadow fleet”; ROE changed to allow tracking/sabotage-suspect vessels; UK-led JEF upping efforts to track threats to subsea infrastructure at Northwood HQ; NATO allies assist via UK-hosted MARCOM and NATO’s Baltic Sentry ensuring Russian ships can’t operate covertly near NATO)[20][22]

• NATO – Lawmakers warn of serious shortfalls in NATO ASW capabilities, NATO Parliamentary Assembly News, 13 Oct 2019. (Report from London: NATO faces growing Russian sub threat but ASW skills “atrophied to dangerous levels”; Alliance must urgently rebuild ASW across full spectrum; calls for boosting defence investment especially on MPAs, ASW frigates, helos, acoustic detection, tactical subs[72][10]; also increase focus on undersea cable threats; notes NATO steps to strengthen command structure and more naval exercises starting to address gap[117][59])

• NATO – NATO’s maritime activities (NATO official topic page, updated 2025). (Overview: NATO maritime forces deter and counter threats including to maritime critical infrastructure; Allies improving info-sharing, tracking, attribution of incidents; developing innovative surveillance and tracking tech; synchronizing with non-military actors to protect infrastructure[35])

• RAND Europe – James Black et al., “Evolving threats to critical undersea infrastructure: Implications for European security and resilience”, RAND Perspective, Jun 2025[62][94]. (Analyzes rising CUI threats: as Europe relies more on undersea assets, they become higher-value targets; notes more automation can increase vulnerability to cyber attack; highlights that proliferation of UUVs, USVs and UAVs is double-edged – they help monitor and defend but also give adversaries new tools for hybrid attacks; CUI attractive to hostile states and non-states due to unique vulnerabilities and high impact; recommends improved coordination, national CUI protection strategies, regular risk assessments, and tech investments; urges NATO to prioritize surveillance and resilience measures, e.g. joint naval exercises and intelligence sharing to counter Russian naval activities)[62][94]

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