It Doesn't Matter if Baltic Submarine Cable Cuts Were Sabotage

November 21, 2024

The recent severing of submarine cables in the Baltic Sea has brought to the forefront the critical vulnerabilities surrounding the infrastructure that underpins modern society. On November 17, the BCS East-West Interlink cable, owned by Arelion and spanning from Lithuania to Sweden, was severed.¹ Shortly after, on November 18, the C-Lion1 submarine cable, owned by Cinia² and extending from Finland to Germany, was also severed.³ These incidents have prompted extensive debate regarding whether the severances were accidental or acts of deliberate sabotage, with Germany’s Minister of Defense, Boris Pistorius, leaning towards the latter.⁴ Irrespective of causation, the imperative that all nation states must embrace is identical. We must immediately take steps to enhance submarine cable redundancy, advance technological capabilities of the cables themselves, and fortify state posture around these critical assets as key national security goals. Given that submarine cables account for over 95% of international internet traffic,⁵ they are the arteries of global communication, and their security is central to the seamless functioning of an interconnected society.

The strategic interest in undersea infrastructure is not new, and Russian activities have repeatedly highlighted these vulnerabilities. American intelligence officials have reported increased Russian activity⁶ in proximity to critical submarine cable infrastructure. Instances such as Russian agents scouting cable landing stations in 2015,⁷ and a Russian spy vessel getting uncomfortably close to critical infrastructure⁸ in the Irish Sea in November 2024, underscore the vital significance of these cables. This increasing scrutiny from state actors is symptomatic of a broader trend that places the resilience of submarine cable networks under constant threat. With more than 750,000 miles of submarine cables traversing the globe, safeguarding their integrity and ensuring sufficient redundancy is an immense challenge that demands international cooperation between private and government entities and proactive policy measures.

A fundamental priority for enhancing submarine cable security is the pursuit of increased redundancy. The Baltic incidents reveal that while some level of redundancy is embedded in current systems, it is insufficient when faced with coordinated attacks or multiple points of failure. An analysis conducted by Réseaux IP Européens Network Coordination Centre (RIPE NCC) illustrated that the severance of the Baltic cables resulted in an increase in latency of 15ms between Sweden and Lithuania and 10ms between Germany and Finland.⁹ While these latencies may appear negligible, they underscore the intrinsic dependency of modern communications on uninterrupted cable infrastructure. More significantly, the analysis highlights that while the internet is inherently resilient enough to reroute data around damaged nodes, the current redundancy must be significantly expanded to mitigate intentional threats from state actors and ensure continued functionality under coordinated stress.

Redundancy is not merely about deploying additional cables but rather about ensuring true geographic path diversity. The most flagrant example is in submarine cable path aggregation through the Red Sea, where 90% of Europe-Asia traffic transits through a single corridor. In March of 2024 three cables were attacked, which impacted approximately 25% of internet traffic transiting ¹⁰ the Red Sea. It is currently an extreme exposure that places international communications at significant risk.

As of 2024, between 100 and 150 submarine cables are severed annually, largely due to inadvertent incidents involving fishing equipment or ship anchors.¹¹ Given the frequency of such occurrences, redundancy must be treated as a baseline requirement, not as an exception. Further, heightened redundancy would significantly complicate attempts by either state or non-state actors to cause large-scale telecommunications disruptions. Russia’s continued scrutiny of undersea infrastructure suggests the strategic value that adversarial states perceive in targeting such assets as part of broader geopolitical maneuvers.

Increased redundancy is not only crucial for mitigating physical threats but also for sustaining the reliability of global communications. Submarine cables are essential to international commerce, banking, and the digital communications that underpin daily life. Any disruption in these cables can have catastrophic consequences, economically and socially. Governments and private sector stakeholders must coordinate to assess vulnerabilities systematically and invest in creating backup routes to minimize the potential impact of disruptions. Collaboration between private and public entities is vital to ensuring that global connectivity is maintained even under adverse conditions.

Another pivotal dimension of submarine cable security lies in the adoption and advancement of smart cable technology. Traditionally, submarine cables served a single function—as conduits for communication. However, contemporary advancements are enabling these cables to be embedded with smart sensors capable of environmental monitoring. Smart submarine cables, which integrate sensors roughly every 70 kilometers, can detect and measure seafloor motion, variations in water pressure, and changes in temperature.¹² This sensor capability is not only instrumental for environmental research¹³ but is also critical for securing the cables. Enhanced situational awareness along the seabed could allow authorities to detect suspicious activity or accidental damage before the perpetrating vessel leaves the area.

The potential of smart submarine cable technology to transform underwater infrastructure from passive conduits into proactive security tools is significant. By embedding sensors, these cables can relay real-time data to authorities, providing crucial information on both natural occurrences and anthropogenic activities along the seabed. Such data is instrumental in responding swiftly to accidental damages and deterring acts of sabotage. The successful implementation of these technologies will necessitate concerted efforts from governments, private enterprises, and multinational bodies, emphasizing subsidies and incentives to encourage adoption.

Governmental support, including subsidies, will be critical in accelerating the deployment of smart submarine cables. Increasing the density of sensors and applying smart technologies to both newly deployed and replacement cables will yield a more granular and timely picture of potential disruptions. Enhanced sensor density will enable pinpointing the precise location and timing of severances, thereby facilitating rapid responses. In cases of deliberate tampering, these sensors will provide critical data that could be provided to government agencies, allowing them to more efficiently identify the perpetrators. Thus, investing in smart cable infrastructure not only augments the overall resilience of the network but also serves as a deterrent against malign actors by making evasion significantly more difficult.

Additionally, the dual-use aspect of smart technology bridges infrastructure security and environmental science. Smart cables, with their integrated monitoring capabilities, have the potential to contribute valuable data to environmental research while simultaneously enhancing security. For instance, early detection of underwater seismic activity or tsunamis could provide essential warning time to coastal communities, thereby mitigating loss of life. Dual-use technologies represent an attractive investment for nations seeking to improve security while delivering broader societal benefits.

As climate change accelerates, monitoring the impact of changing ocean temperatures and conditions through smart submarine cables offers essential data for global climate models. The dual-purpose functionality of smart cables provides policymakers with a compelling rationale for infrastructure investment. Not solely for security but also as part of a broader commitment to environmental stewardship and scientific understanding. By addressing multiple policy goals simultaneously, investments in smart cable technologies can enhance resilience, contribute to climate research, and fortify critical infrastructure.

Equally critical to the advancement of submarine cable security is fortifying state posture regarding this vital infrastructure. While smart cables provide an enhanced passive defense mechanism, active protection is indispensable for comprehensive security. The recent decision by the United States Federal Communications Commission (FCC) to review submarine cables as critical infrastructure¹⁴ is a welcome but long overdue acknowledgment of their importance. Initiatives such as Team Telecom, a cross-agency group tasked with evaluating the national security implications of undersea cables¹⁵ landing on U.S. shores, must be further strengthened to ensure that infrastructure does not become a strategic liability that could be easily exploited by adversaries.

International collaboration is essential for the effective security of submarine cables. These cables traverse multiple jurisdictions, involving an array of stakeholders, including nations, corporations, and international bodies. Establishing global norms and cooperative frameworks for protecting undersea infrastructure can enhance resilience against potential threats. Multilateral agreements to standardize cable protection, foster information sharing, and coordinate responses to incidents could improve the collective security of submarine networks.

Bilateral and multilateral partnerships are instrumental in securing submarine cable infrastructure. Nations with shared interests in maintaining open, secure communication channels should work in concert to establish joint task forces, conduct regular risk assessments, and develop coordinated response strategies. These partnerships can promote more effective information exchange and provide a unified defense against potential adversarial threats. The pooling of technological expertise and financial resources through international cooperation is fundamental to reinforcing the robustness of submarine cable networks.

Physical security measures also constitute a crucial component of submarine cable protection. Although patrolling the entirety of submarine cables, spanning thousands of miles along the ocean floor, is impractical, focused efforts can enhance security at critical junctures. Submarine cable landing stations, where cables connect with terrestrial infrastructure, represent a significant vulnerability. Governments must invest in fortifying the physical security of these installations to prevent unauthorized access and potential acts of sabotage. Additionally, remote monitoring technologies, such as smart submarine sensors, must be employed to provide oversight across areas that are otherwise impractical to patrol. The combination of enhanced physical security and technological monitoring can create a resilient defense against both accidental damage and deliberate threats.

The human element is an often-overlooked aspect of infrastructure security. Efforts should be made to engage local communities in the coastal areas where submarine cable landing stations are situated. Community awareness initiatives and local partnerships can foster vigilance and encourage the reporting of suspicious activities. By involving local stakeholders, governments can establish an additional layer of security that complements technological measures. This community-focused approach, paired with enhanced physical and technological security, represents a comprehensive defense strategy against a diverse array of threats.

Community engagement is critical not only for enhancing vigilance but also for building trust between the public and authorities tasked with safeguarding critical infrastructure. By educating coastal communities on the strategic importance of submarine cables and the potential threats they face, governments can foster a culture of collaboration and mutual support. This inclusive approach is instrumental in early threat detection and mitigation, as community members are often the first to observe and respond to suspicious activities.

The severing of submarine cables in the Baltic Sea is reminiscent of similar uncertainties surrounding other infrastructure damage, such as the Nord Stream gas pipeline explosion in 2022. Despite thorough investigations, the responsible party remains unidentified, underscoring the challenge of attribution in incidents involving critical infrastructure.¹⁶ Whether the Baltic cable cuts were acts of sabotage or merely accidental, the broader imperative remains clear, submarine cables must be protected, strengthened, and made resilient to withstand both deliberate attacks and natural disasters.

The significance of submarine cables in the contemporary era is impossible to overstate. These cables are the backbone of global communications, carrying more than 95% of international internet traffic. Every financial transaction, communication, and data transfer that crosses international boundaries depends on the continued integrity of these undersea links. The interconnected nature of global economies and societies hinges on this largely unseen infrastructure beneath the ocean’s surface. This is critical infrastructure that is, in many cases, simply resting on the sea floor in unpatrolled international waters. The recent damage to Baltic cables is a reminder to global governments, urging them to rethink how they safeguard critical infrastructure in an era where digital connectivity is essential.

Securing this infrastructure requires a holistic strategy that encompasses redundancy, technological advancement, and enhanced security protocols. By advocating for increased redundancy, nations can make the global internet more resilient to large-scale disruptions, minimizing the risk that arises from individual cable failures. Geographic path diversity must be prioritized to avoid creating critical bottlenecks that could be exploited by malicious actors or accidental damage. Building a resilient web of connectivity that can absorb shocks without compromising functionality is crucial for ensuring global stability in an increasingly unpredictable world.

Adopting smart submarine cable technology is a forward-thinking solution that not only enhances security but also contributes to environmental monitoring and research. By integrating sensors along cables, authorities gain a comprehensive understanding of seafloor conditions, allowing them to detect threats in real time and respond effectively. Government incentives, such as subsidies for adopting smart technologies, can encourage private companies to invest in these innovations, ensuring that both new and existing cables are equipped to meet the evolving challenges of the twenty-first century. Smart sensors are not merely tools for scientific advancement; they are indispensable elements of modern infrastructure security.

Furthermore, fortifying state posture around submarine cable infrastructure is crucial for deterring adversarial actions and safeguarding national interests. Governmental entities, such as Team Telecom in the United States, must take proactive measures to assess risks associated with submarine cables and ensure that they do not become strategic vulnerabilities. Enhanced physical security measures at landing stations and other critical points must be implemented to prevent unauthorized interference. The strategic importance of submarine cables necessitates a multifaceted approach to security that integrates technological innovation, physical safeguards, and international cooperation.

The incidents involving the Baltic submarine cables serve as a stark reminder of the vulnerabilities inherent in the infrastructure that supports global communications. Whether these severances were caused by sabotage or negligence is ultimately secondary to the greater necessity of securing these critical assets. Submarine cables must be rendered resilient to withstand both human-induced threats and the forces of nature. As society becomes ever more dependent on digital connectivity, the urgency of securing these networks becomes increasingly evident. Ensuring redundancy, embracing smart technologies, and fortifying security measures are essential steps toward safeguarding the future of global communications. The moment to act is now, before further incidents reveal the fragility of the infrastructure that sustains our interconnected society.