Key Takeaways

• **Digital SLOCs Are Critical: **Submarine cables carry nearly all intercontinental data, underpinning global commerce, finance, defense, and government operations.
• **Chokepoints Heighten Risk: **Corridors such as Bab el-Mandeb, Hormuz, Malacca, the Turkish Straits, and the Panama Canal concentrate maritime and digital traffic, creating systemic vulnerabilities.
• **Cables Remain Fragile: **Accidents, natural hazards, climate stress, and deliberate attacks can disrupt connectivity, with repairs often taking days to weeks.
• **Limited Redundancy and Oversight: **Routes cluster near chokepoints, and private ownership combined with weak international frameworks constrains coordinated protection.
• **High Strategic Stakes: **Disruptions can cascade across financial markets, cloud services, energy logistics, and government operations, emphasising the need for robust risk management and alternative routing.

Introduction: The Hidden Dimension of Global Connectivity

Sea Lines of Communication (SLOCs) have long supported global commerce and security, carrying oil, energy resources, food, industrial raw materials, military cargo, and high-value goods across the world’s oceans. Yet, in today’s economy, this traditional view captures only part of the picture. Beneath these oceans lies a dense network of undersea cables that sustain global digital connectivity—an infrastructure as critical as the shipping lanes themselves, yet often overlooked.

Historically, naval presence, alliances, and international law sufficed to secure maritime corridors. In the 21st century, however, the global economy depends as much on invisible undersea infrastructure as on surface trade. Submarine fiber-optic cables carry 95–99% of intercontinental data traffic, supporting financial markets, cloud computing, logistics, and government communications. Even brief disruptions can ripple across continents, slowing stock exchanges, delaying payments, interrupting supply chains, and reducing military and diplomatic capacity.

Security concerns surrounding undersea SLOCs intensified in Europe in 2023 and 2024 following several high-profile incidents. In October 2023, the Hong Kong–flagged NewNew Polar Bear allegedly damaged two subsea cables and a gas pipeline in the Baltic Sea. On November 17–18, 2024, two subsea communications cables linking Germany to Finland and Lithuania to Sweden were allegedly severed by the Chinese cargo ship Yi Peng 3. North Atlantic Treaty Intelligence (NATO) intelligence further warned that Russia could target undersea cables in retaliation against Western nations supporting Ukraine. In December 2024, a vessel from Russia’s ‘shadow fleet’ reportedly cut an electricity interconnector along with four telecommunications cables in the Gulf of Finland.

In 2025 alone, the International Cable Protection Committee (ICPC) reported 150–200 cable outages worldwide, illustrating the growing fragility of these networks. High-density corridors face weekly disruptions from human activity and environmental stress. As commerce, artificial intelligence (AI), and cloud services expand, demand for bandwidth intensifies, placing unprecedented pressure on a small number of geographically constrained routes. Without deliberate policy intervention, structural vulnerabilities are likely to persist or worsen, creating systemic risks that could surpass traditional maritime blockages.

Global Undersea Cable Infrastructure: Scale and Scope

As of early 2025, an estimated 570 active submarine cable systems span the world’s oceans, with roughly 80 additional networks either under construction or in advanced planning stages. Collectively, these fiber-optic systems stretch approximately 1.4–1.5 million kilometre along the seabed, forming the backbone of global digital connectivity.

These cables terminate at more than 1,700 landing points worldwide, where they connect to terrestrial networks. The number of landing points has increased steadily, from 1,444 in 2023 to 1,636 in 2024. These points are unevenly distributed, with dense clusters in Asia-Pacific, Europe, and North America. The Middle East and East Africa serve as critical transit zones linking Europe and Asia through narrow maritime corridors.

Rather than spreading uniformly, submarine cables follow a limited number of backbone routes, including the North Atlantic, the Mediterranean–Red Sea corridor, and the Strait of Malacca. While this concentration reflects geographic constraints and economic efficiency, it also creates systemic vulnerability: vast volumes of global data rely on a relatively small set of physical pathways.

This network reveals a paradox of modern connectivity: although digital communications appear instantaneous and borderless, they rely on finite, exposed infrastructure beneath the oceans. Any disruption—accidental, environmental, or deliberate—can cascade across commerce, finance, energy, and government operations worldwide.

Historical Evolution of Undersea Cables

The history of undersea cables spans over 160 years, reflecting the interplay of technology, commerce, and strategic priorities.

• Telegraph Era: The first successful submarine telegraph cable was laid by the English Channel Submarine Telegraph Company across the English Channel in 1850, enabling near-instant communication between England and France. The transatlantic telegraph cable, first attempted in 1858 and successfully completed in 1866, connected Ireland and Newfoundland. Early cables often failed due to technical limitations and environmental hazards, establishing a pattern of vulnerability that persists today.
• Telephone Era: The 20th century saw the transition from telegraph to telephone cables, culminating with the TAT-1 transatlantic telephone cable in 1956, capable of 36 simultaneous voice calls. Advances in materials, signal amplification, and laying techniques gradually improved durability and performance.
• Fibre-Optic Era: The 1980s and 1990s introduced fiber-optic technology, revolutionising undersea communications by enabling massive volumes of internet data, cloud services, and financial transactions to be transmitted across continents. Today, hundreds of submarine cables crisscross the globe, forming the backbone of the digital economy.

The evolution of undersea cables demonstrates a consistent interplay between commercial incentives, technological innovation, and strategic considerations. Modern technology firms and states continue to invest heavily in undersea infrastructure to expand capacity, enhance resilience, and secure strategic access in an increasingly digitised world.

Vulnerability and Repair Challenges

Despite their importance, submarine cables remain fragile. They can be damaged by ship anchors, fishing activity, undersea earthquakes, landslides, and deliberate sabotage. Even a single severed cable can disrupt thousands of kilometres of connectivity, affecting internet traffic, financial transactions, and government communications almost immediately.

Repairing undersea cables is complex, costly, and time-consuming. Specialised cable-laying vessels must locate the damaged segment, retrieve it, splice new fiber, and redeploy it, often under challenging weather or deep-water conditions. Operations may occur in politically contested waters, where conflict or non-state actors complicate access, raise security risks for repair crews, and delay restoration. Traffic is usually rerouted during repairs, but additional interference can create cascading failures.

Concentration along narrow corridors elevates systemic risk. In September 2025, multiple major systems—including SEA-ME-WE 4 and India–Middle East–Western Europe (I-ME-WEW)—were severed near Jeddah, Saudi Arabia, degrading internet performance across India, Pakistan, the UAE, and the broader Middle East. Earlier disruptions on the Asia Africa Europe-1 (AAE-1) cable system similarly reduced international bandwidth, illustrating how localised incidents can have regional or global consequences.

Undersea Cables: The Hidden Frontlines of Modern Conflict

In 2024 and 2025, undersea cables—the invisible arteries of global internet and communications—have become increasingly central to strategic concerns. A series of disruptions highlighted both the vulnerability of these infrastructures and their geopolitical significance.

The Baltic Sea emerged as a hotspot in late 2024, with simultaneous damage reported to major submarine cables, including BCS East West Interlink and C Lion1. The timing and concentration of these breaks prompted European officials to investigate possible sabotage amid rising geopolitical tensions. While investigations focused on suspicious vessel movements, no conclusive attribution was made. Shortly thereafter, the EstLink 2 cable and several telecom lines in the Gulf of Finland were damaged, likely by a dragged anchor, demonstrating how indirect maritime activity in contested waters can severely disrupt connectivity.

By 2025, similar patterns appeared in the Asia-Pacific region. Commercial vessels operating near undersea cables connecting Taiwan raised alarms over potential reconnaissance or sabotage. Although direct evidence of deliberate attack remained limited, these incidents reflect concerns that strategic undersea networks could be targeted as part of hybrid warfare or geopolitical leverage.

The Red Sea, amid ongoing conflict, has also become a zone of compounded risk. Submarine cables such as AAE-1, EIG, and SEACOM suffered cuts in 2024–2025, coinciding with missile attacks and maritime disruptions attributed to Yemen’s Houthi movement. While direct sabotage by non-state actors has not been conclusively proven, regional authorities and media frequently associate cable damage with Houthi operations against commercial shipping, underscoring the blurred lines between conflict, collateral damage, and intentional attacks.

Severing undersea cables deliberately is technically challenging, but geography heavily influences feasibility. Shallow or coastal areas make cables more accessible, allowing even unsophisticated methods—such as dragging heavy anchors—to cause damage without advanced military-grade technology. The combination of geopolitical tension, shallow water access, and dense traffic creates a persistent vulnerability for key digital corridors.

Strategic Maritime Chokepoints

Maritime chokepoints are critical junctures where global trade and digital infrastructure converge. These narrow corridors concentrate both ships and undersea cables, amplifying systemic risk. While each chokepoint has unique vulnerabilities, they share the characteristic of concentrated exposure, making them essential to both economic and strategic planning.

Red Sea and Bab el-Mandeb Strait

The Red Sea, connecting to the Mediterranean via the Suez Canal, and its southern gateway, the Bab el-Mandeb Strait, exemplify the intersection of physical and digital SLOCs. The Suez Canal handles approximately 12–15% of global trade, while the Bab el-Mandeb—only 30 kilometres wide at its narrowest—connects the Red Sea to the Gulf of Aden and the Indian Ocean.

Beneath the surface, this corridor hosts one of the densest clusters of submarine cables in the world, including SEA-ME-WE 3, SEA-ME-WE 4, FLAG, EIG, and Telecom Egypt North (TE North). Up to 90% of Europe–Asia data flows traverse these routes, and the Bab el-Mandeb alone carries roughly 17% of global internet traffic. Cable clustering, while cost-effective, heightens systemic vulnerability: a single incident can disrupt multiple systems simultaneously, producing cascading effects across continents.

Since late 2023, Houthi attacks on commercial vessels in the Bab el-Mandeb Strait have underscored the strategic leverage inherent in chokepoints. Missile and drone strikes forced shipping to reroute around the Cape of Good Hope, adding weeks to transit times, increasing fuel costs, and raising insurance premiums. Unlike shipping delays, cable outages affect digital networks almost instantaneously—slowing financial transactions, degrading cloud services, and disrupting government communications within hours.

Operation Prosperity Guardian (OPG), launched by the United States (US) in December 2023, aimed to deter Houthi threats and protect navigation. Follow-up operations—Poseidon Archer (OPA) and Rough Rider (ORR)—sought to further degrade Houthi capabilities. While partially effective, these operations lacked broad international support and largely failed to address undersea infrastructure, illustrating the limits of traditional naval strategies in safeguarding digital SLOCs.

Strait of Hormuz

The Strait of Hormuz, a 40-kilometre-wide corridor, is vital for global energy flows, handling roughly 20% of worldwide oil consumption and one-fifth of LNG shipments. Countries bordering the strait—Saudi Arabia, Iran, the UAE, Kuwait, Iraq, and Qatar—depend on it for exports to energy-consuming nations, especially in Asia.

Strait of Malacca

Multiple submarine cable systems traverse the Persian Gulf and Strait of Hormuz, connecting the Middle East to Europe, South Asia, and Africa. Key networks include Gulf Bridge International (GBI), Fiber-Optic Link Around the Coast of the Arabian Gulf Network (FALCON), Europe India Gateway (EIG), I-ME-WE, and SEA-ME-WE 6 (Al Khaleej branch). Disruptions here could ripple simultaneously through energy markets and digital systems, highlighting the dual vulnerability of this corridor. Redundancy—via alternative pipelines, shipping routes, and parallel cables—is essential to mitigate potential disruptions.

The Strait of Malacca, the shortest sea route between the Indian and Pacific Oceans, is among the busiest and most economically significant chokepoints globally. Annually, over 80,000 vessels transit the strait, carrying goods worth trillions of dollars. Roughly one-quarter to one-third of global seaborne trade passes through this corridor.

Dense networks of submarine cables closely follow the shipping lanes. Major systems include Asia America Gateway (AAG), Asia Pacific Gateway (APG), South East Asia–Japan Cable 2 (SJC2), AAE-1, and SEA-ME-WE 4 and SEAMEWE-5. Together, they support financial markets, cloud services, manufacturing ecosystems, and regional data centers. Congestion, piracy, geopolitical tension, and climate events pose persistent risks, making investments in alternative routes and cable redundancy increasingly vital.

Turkish Straits (Bosporus and Dardanelles)

The Bosporus and Dardanelles connect the Black Sea to the Mediterranean, hosting over 40,000 commercial vessel transits annually. Narrow channels, heavy traffic, and seasonal weather complicate navigation. Submarine cables linking Eastern Europe, the Caucasus, and Mediterranean networks include KAFOS (Istanbul to Mangalia via Varna), MedNautilus (Türkiye to Greece, Italy, Cyprus, and Israel), and the Caucasus Cable System (Bulgaria to Georgia), which is the sole direct connection between Georgia and Europe.

Türkiye’s role as a NATO member controlling access between the Black Sea and Mediterranean makes its stewardship critical. Secure transit of energy and grain exports depends on Türkiye’s ability to regulate naval and commercial traffic.

Panama Canal Approaches

The Panama Canal, linking the Atlantic and Pacific Oceans, is a major maritime chokepoint. In 2024, approximately 13,000–14,000 vessels transited the canal, carrying nearly 300 million tons of cargo. Environmental stressors, including droughts and fluctuating water levels, occasionally reduce throughput, forcing rerouting around Cape Horn and adding significant delays.

Submarine cables land on both coasts of Panama, connecting North America, Latin America, and the AsiaPacific. Key systems include Pacific Caribbean Cable System (PCCS), MAYA1 and its upgraded successor MAYA1.2, Americas Region Caribbean Optical Submarine Cable System (ARCOS 1), Pan American Crossing (PAC), South American Crossing (SAC), and Curie. The original MAYA1 system has been a longstanding subsea link in the Caribbean and Central America.

The nextgeneration MAYA1.2 is a strategic reconfiguration that doubles the capacity of the original cable—providing up to 4 Tbps of ring design capacity across three landing points (Florida; Honduras; and Grand Cayman)—with modernised technology, lower latency and enhanced resilience, strengthening international connectivity for businesses, governments, and communities in the region.

Completion is expected by the first half of 2026 as part of broader investments in futureready digital infrastructure. These networks are critical not only for maritime trade but also for global digital connectivity.

Table 1. Key Global Maritime Chokepoints and Their Digital Infrastructure

Chokepoint	Width / Capacity	Trade Volume	Key Submarine Cables	Key Risks	Affected Regions
Bab el-Mandeb Strait	30 km	~12% global trade	SEA-ME-WE 3, SEA-ME-WE 4, FLAG, EIG, TE North	Conflict, congestion, sabotage, non-state actor attacks	Europe, Middle East, Asia
Strait of Malacca	2.8 km (narrowest)	25–33% global trade	AAG, APG, SJC2, AAE-1, SEA-ME-WE 4, SEA-ME-WE 5	Congestion, piracy, geopolitical tension, climate	East Asia, global trade
Strait of Hormuz	40 km	20% oil, 20% LNG	GBI, FALCON, EIG, I-ME-WE, SEA-ME-WE 6 (Al Khaleej branch)	Geopolitical tension, sabotage, technical failures	Asia, Europe, Middle East
Turkish Straits	Narrow channels	40,000 vessels/yr	KAFOS, MedNautilus, Caucasus Cable System, Kardesa (planned)	Navigational hazards, geopolitical tension, seasonal weather	Europe, Black Sea region
Panama Canal Approaches	300 m locks	~300 million tons/yr	PCCS, MAYA-1, MAYA-1.2, ARCOS-1, PAC, SAC, Curie, Caribbean Express, Carnival Submarine Network-1	Environmental stress, drought, congestion	Americas, Asia-Pacific

Source: Authors

Chokepoints concentrate risk for both maritime trade and digital connectivity. While shipping can reroute over time, undersea cables carry instantaneous flows of data. Even advanced naval protection cannot prevent accidents or natural hazards on the ocean floor, making redundancy, resilience planning, and international coordination critical for mitigating systemic disruptions.

Expanding Global Connectivity: Undersea Cable Projects

As global reliance on digital infrastructure grows, governments and private firms are investing heavily in undersea cable projects to expand capacity, diversify routes, and enhance resilience. These initiatives serve dual purposes: supporting commercial needs such as cloud computing, AI workloads, and financial networks, while also mitigating strategic vulnerabilities associated with concentrated chokepoints.

Major technology companies have become key actors in submarine cable deployment. Meta’s Project Waterworth, spanning approximately 50,000 kilometres across five continents, links the US, India, Brazil, and South Africa. The project establishes an alternative digital backbone designed to support AI and cloud traffic while bypassing congested chokepoints such as the Red Sea and Suez Canal.

In January 2024, Google advanced the Humboldt Cable, a 12,000-kilometre trans-Pacific link connecting South America, French Polynesia, and Australia. This project provides the first direct digital connection between South America and the Asia-Pacific region, creating a new trans-Pacific pathway for data that avoids traditional North American and European routes.

Consortium-led initiatives also expand capacity along historically congested and geopolitically sensitive corridors. These include SEA-ME-WE 6 (Southeast Asia–Middle East–Europe) and SJC2, which run parallel to older, heavily trafficked routes to increase redundancy and regional resilience.

Regional projects strengthen local connectivity and digital sovereignty. The Daraja Cable, a 4,110-kilometere system linking Salalah (Oman) to Mombasa (Kenya) and backed by Safaricom and Meta, enhances East Africa’s internet resilience and reduces reliance on traditional chokepoints. The Kardesa Cable, a €100 million joint initiative by Ukraine and Vodafone, is planned to connect Bulgaria, Georgia, Türkiye, and Ukraine by 2027. Designed to bypass geopolitically sensitive routes, it will add over 500 terabits per second of capacity to the Black Sea region.

Despite these expansions, the physical geography of the oceans and economic considerations often keep new cables aligned with traditional chokepoints, perpetuating structural vulnerabilities. Nonetheless, these investments reflect a growing recognition that undersea infrastructure is inseparable from national security and economic stability. States increasingly view cable ownership, routing, and operational control as instruments of digital sovereignty, while private operators gain both performance and strategic advantages.

Table 2. Selected Major Undersea Cable Projects

Project	Route	Length (km)	Key Purpose	Redundancy Feature
Project Waterworth	US–India–Brazil–South Africa	50,000	AI, cloud, global connectivity	Bypasses congested chokepoints
Humboldt Cable	South America–Asia-Pacific	12,000	Direct trans-Pacific link	Alternative to North America/Europe
SEA-ME-WE 6	Southeast Asia–Middle East–Europe	20,000+	Expands capacity	Supplement to SEA-ME-WE 5
SJC2	Southeast Asia–Japan	9,000	Regional high-speed connectivity	Parallel route to congested nodes
Daraja Cable	Salalah (Oman)–Mombasa (Kenya)	4,000	East African regional link	Improves redundancy
Kardesa Cable	Black Sea	1,200	Bypass sensitive routes	Geopolitically resilient

Source: Authors

These projects underscore the strategic importance of redundancy, route diversification, and capacity expansion in the modern digital economy. By creating alternative pathways, operators and states can mitigate systemic risks, reduce dependence on vulnerable chokepoints, and enhance resilience against both environmental and geopolitical disruptions.

Undersea infrastructure—including both submarine telecommunications and electricity cables—is critical to global commerce, finance, energy security, and government operations. Yet these networks remain exposed to physical, environmental, and geopolitical risks. Effective governance is essential to safeguard these dual-use lifelines and ensure resilience against accidental damage, natural hazards, and deliberate interference.

Policy and Governance Challenges

US–China Great Power Competition

The strategic rivalry between the US and China spans global maritime interests, stable land borders, and nuclear capabilities. In the South China Sea, tensions manifest through Chinese construction of artificial islands, deployment of maritime militias, and state-controlled fishing fleets—practices that can function as hybrid or cognitive warfare. US freedom of navigation operations (FONOPs) further complicate the picture.

These overlapping activities highlight the critical importance of securing maritime and undersea lines of communication that underpin global trade and digital connectivity. A misstep in this arena could disrupt both commercial and strategic networks, illustrating the stakes of modern submarine cable security.

Legal Vulnerabilities and Historical Foundations

Despite their centrality, undersea cables remain vulnerable. Their physical exposure, publicly available locations, and relative ease of access make them susceptible to accidental damage, natural hazards, or deliberate interference. Hybrid or grey-zone attacks—designed to mimic accidents—further complicate attribution, legal recourse, and deterrence.

The legal framework governing submarine cables has deep historical roots. The 1884 Convention for the Protection of Submarine Telegraph Cables represented the first multilateral attempt to regulate and safeguard undersea infrastructure. While foundational, it addressed telegraph cables, individual liability, and accidental damage by ships, leaving modern fibre-optic networks largely unaddressed.

Today, the United Nations Convention on the Law of the Sea (UNCLOS) forms the core framework. Articles 87 and 112 affirm the right to lay cables on the high seas and continental shelves, while Articles 113–115 obligate states to criminalise damage and establish liability rules. However, these provisions rely heavily on domestic enforcement and offer limited clarity regarding covert or state-sponsored interference, leaving gaps in accountability for acts that fall below the threshold of armed conflict. Despite clear obligations under Article 113, many states have yet to integrate these rules into domestic law.

Call to Diversify Undersea Cables

Southeast Asia’s undersea cable infrastructure remains highly concentrated, increasing regional vulnerability. The global market functions as an oligopoly, with Japan (41%), the US (20%), China (19%), France (18%), and Germany (2%) dominating ownership and technical capacity. A disruption along a single route or major operator could have outsised effects on regional connectivity, commerce, and financial systems.

Technical, economic, and geopolitical constraints further complicate diversification. Cable deployment requires significant capital, specialised vessels, multi-state permits, and routes that navigate environmental and geographic limitations. Political sensitivities and strategic competition hinder multilateral initiatives. Expanding capacity, diversifying routes, and spreading ownership are central to reducing reliance on congested chokepoints and strengthening network resilience.

Private Ownership and Multi-State Responsibilities

Most submarine cables are owned by private consortia of technology firms and telecom operators spanning multiple jurisdictions. While these operators maintain technical expertise, they have limited obligations to integrate networks into national security frameworks. This intersection of public interest and private ownership raises questions about who is responsible for protecting infrastructure that serves multiple states, economies, and populations.

Other Critical Seabed Cables

Seabed power lines and pipelines form another essential layer of undersea infrastructure, supporting energy security and economic resilience. High-voltage electricity cables, such as the Viking Link (UK–Denmark) and North Sea Link (UK–Norway), balance supply and demand across national grids and facilitate renewable energy integration. In the Mediterranean, projects like GRITA 2 (Italy–Greece) and the Corsica–Italy electricity link enable cross-border energy flow and regional reliability.

Seabed pipelines also connect offshore oil and gas facilities to onshore refineries and export terminals, ensuring steady delivery of energy resources. Like telecommunications cables, these conduits are vulnerable to accidents, deliberate interference, and environmental hazards. Even small incidents can have disproportionate consequences, disrupting power transmission, halting offshore operations, and creating cascading effects in global energy markets.

The strategic significance of seabed electricity cables and pipelines is growing alongside offshore energy production. Protecting these assets requires coordinated monitoring, maritime regulation, redundancy planning, and rapid repair capabilities—approaches closely mirroring those necessary for submarine telecommunications networks. Energy and digital infrastructures face many of the same dangers, underscoring the need for comprehensive policy frameworks that safeguard both lifelines beneath the sea.

Strategic Policy Challenges

Policymakers face complex dilemmas: How can deliberate interference be deterred without escalating tensions? To what extent should governments prioritise security over commercial and economic considerations? How can risk management frameworks account for the dual-use nature of submarine cables, which support civilian, financial, and military communications simultaneously?

Addressing these challenges requires a multifaceted approach:

• Developing international norms and best practices for cable protection.
• Establishing multilateral agreements for real-time information sharing and joint monitoring of vulnerable corridors.
• Creating rapid-response mechanisms for cable repair and mitigation.
• Promoting confidence-building measures among states in strategic chokepoints such as Bab el-Mandeb, Malacca, and the Turkish Straits.
• Investing in redundancy, network resilience, and alternative routing to reduce systemic risk.

Progress is constrained by geopolitical fragmentation. Rising tensions in the Indo-Pacific, the Middle East, and Eastern Europe, coupled with divergent national interests and legal interpretations, make coherent governance extremely difficult. The potential economic, security, and societal costs of undersea cable disruption are enormous. Piecemeal or reactive measures are insufficient; proactive, coordinated policies are essential to protect the infrastructure underpinning global commerce, digital connectivity, and strategic stability.

Securing the Invisible Frontlines

The infrastructure beneath the waves is as strategically vital as what transits above them. Submarine cables, seabed power lines, and pipelines are the hidden arteries of global commerce, communication, and energy. Despite their central importance, these networks remain fragile, exposed to environmental hazards, accidents, and deliberate interference. Traditional naval presence—patrolling shipping lanes, escorting tankers, or projecting military power—can protect surface traffic but offers little defense for these undersea lifelines.

This vulnerability demands a new approach to maritime strategy. Defense planners, policymakers, and infrastructure operators must increasingly treat digital and energy SLOCs as contested domains. Effective management requires integrating intelligence, rapid-response capabilities, redundancy planning, and risk mitigation into broader maritime and security strategies.

Emerging Strategic Thinking

Recent incidents illustrate these risks. The September 2025 Red Sea outages, repeated disruptions in the Strait of Malacca, and incidents in the Baltic and Gulf of Finland demonstrate how a single event can cascade across trade, energy, and digital networks within minutes. The systemic consequences of such disruptions extend far beyond the immediate corridor, threatening economic stability and national security.

Hybrid and Environmental Threats

Undersea networks face intersecting pressures. Hybrid threats—including piracy, insurgency, terrorism, and state-directed operations—exploit chokepoints, while climate-driven events and technical failures remain constant risks. Each corridor carries a unique risk profile: some are highly exposed to extreme weather, others to geopolitical tension—but all share the danger of concentrated exposure.

The interconnectedness of physical and digital networks means that disruptions propagate rapidly. Unlike maritime shipping, which can be rerouted over days or weeks, data flows along submarine cables are near-instantaneous, magnifying the impact of any interruption.

Expanding Capacity and Redundancy

Investments in new infrastructure highlight the strategic imperative of redundancy. Projects such as Project Waterworth, the Humboldt Cable, and the Kardesa Cable demonstrate that alternative routing can reduce dependence on congested chokepoints. However, the realities of geography, cost, and economic incentives mean that risk will never be fully eliminated.

Diversifying routes, expanding capacity, and embedding resilience are no longer merely commercial concerns—they are strategic imperatives. Effective risk mitigation requires a combination of infrastructure planning, operational oversight, and international coordination.

A Holistic Approach to Security

Securing these invisible frontlines demands a comprehensive strategy:

• Integrating maritime operations with cyber and technical surveillance.
• Strengthening international cooperation and intelligence-sharing mechanisms.
• Establishing rapid repair and mitigation capabilities.
• Prioritising redundancy and alternative routing to minimise systemic exposure.

Submarine infrastructure is not merely a commercial convenience; it is a core component of national security, global stability, and strategic power. The ability of states and private actors to protect and manage these networks will shape the resilience of global trade, energy flows, and the digital economy for decades to come.

Conclusion: The Digital Achilles’ Heel—Undersea Cables and the New Battlefield

In the 21st century, geopolitics is no longer confined to land borders or visible naval fleets; it now courses invisibly along the seabed. Undersea cables—carrying nearly all intercontinental data—have transformed traditional SLOCs into digital lifelines, linking commerce, finance, defense, and government in real time. Yet these lifelines are concentrated along a handful of chokepoints—Bab el-Mandeb, the Strait of Malacca, Hormuz, the Turkish Straits—where physical geography, commercial incentives, and historical infrastructure converge. The result is a paradoxical vulnerability: the very efficiency that allows globalised economies to function also renders them fragile, creating a digital ‘Achilles’ heel’ that could be exploited in hybrid or kinetic conflicts.

States are particularly exposed. Disruption of undersea networks can immediately compromise national security, intelligence sharing, and military readiness, leaving governments scrambling to maintain command-and-control capabilities. People and communities, too, face cascading effects: communication outages can hinder emergency services, disrupt health and education systems, and isolate populations from essential digital services. Meanwhile, the global financial system—dependent on instantaneous data transfer for transactions, trading, and settlements—rests atop a single, fragile jugular; even a brief outage at a chokepoint could trigger cascading losses across markets, destabilise currencies, and undermine trust in institutions.

As states and private actors vie for control, ownership, and routing of submarine networks, undersea cables have emerged as critical instruments of geopolitical leverage, shaping the contours of global competition far beyond the surface of the oceans. Looking forward, the geostrategic implications are stark: the undersea realm will increasingly define the balance of power between states and blocs. Disruptions—whether accidental, environmentally driven, or deliberate—can cascade instantly through markets, cloud infrastructures, and military networks, making chokepoints arenas of latent conflict where a single incident reverberates globally.

Investments in redundancy, alternative routing, and regional autonomy are no longer merely commercial calculations; they are acts of strategic foresight. In a world where the invisible architecture of connectivity underpins the visible architecture of power, the ability to secure, monitor, and project influence over undersea networks will shape not only economic resilience but also the future of great-power competition, hybrid warfare, and digital sovereignty. Those who control the cables may well control the 21st-century battlefield—and, by extension, the global order itself.

About the authors:

• Scott N. Romaniuk—Senior Research Fellow, Centre for Contemporary Asia Studies, Corvinus Institute for Advanced Studies (CIAS); Department of International Relations, Institute of Global Studies, Corvinus University of Budapest, Hungary.
• Amparo Pamela Fabe—Professor, National Police College, Philippines; Fellow, Brute Krulak Center, US Marine Corps University; Maritime Security Fellow, Maritime Research Center, Pune, India.