The strategic, economic significance of subsea cables cannot be overstated. Telecommunications companies rely on them to deliver international voice and data services,. fFinancial markets depend on them to transmit stock trades and currency transactions in milliseconds,. cCloud services and data centers rely on them for uninterrupted data flow, and governments count on these channels for secure communication. A severed cable, therefore, isn’t merely an infrastructure problem; —it’s a systemic risk with economic, technological, and geopolitical implications.
Recent events have highlighted just how vulnerable these networks are. In September 2025, a cluster of cables in the Red Sea was severed, causing significant disruptions to internet traffic across Asia, the Middle East, and Europe. Latency spiked, cloud-based services slowed, and financial institutions reported delays in cross-border transactions.
Around the same time last year, cables in the Baltic Sea connecting Finland and Germany were damaged, with early investigations suggesting the possibility of sabotage. These incidents underscored the fact that, while most digital traffic travels invisibly, it is far from invincible.
Further compounding concerns, intelligence agencies have tracked suspicious activity by specialized vessels such as Russia’s Yantar, which has loitered near key junction points of European subsea cables. A July 2025 report by Recorded Futuretitled ‘The Escalating Global Risk Environment for Submarine Cables’ warned that state-backed attacks on undersea cables, particularly linked to Russia and China, are likely to rise as part of hybrid “grey-zone” tactics. Meanwhile, China has developed new deep-sea cable-cutting ships capable of operating at depths of up to 4,000 meters. Such developments suggest that espionage, reconnaissance, and deliberate sabotage are no longer theoretical risks.
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Challenges to Restoration
Repairing damaged subsea cables is a high-stakes, highly technical endeavor. There are fewer than 70 cable-laying and repair ships worldwide, meaning that simultaneous outages can strain the system. The process involves locating the break, which can be thousands of meters below the ocean surface, surfacing the cable, splicing it, and lowering it back to the seabed. Weather conditions, depth, and undersea terrain all complicate this work, and any delay can have cascading effects on global connectivity.
In July 2025, the SHEFA-2 cable, located off the coast of Orkney, was damaged approximately 9 km from shore, disrupting internet service for Shetland, Orkney, and the Faroe Islands. Repair work was slowed not only by limited vessel availability but also by adverse weather conditions, leaving island communities offline for extended periods.
Logistics and geopolitics further complicate cable repair. In some cases, cables run through territorial waters or exclusive economic zones (EEZ) where local permits are required for repair. Tensions between nations, regulatory bottlenecks, and bureaucratic delays can slow response times, leaving critical regions without reliable connectivity for days or even weeks. One example was the AAE-1 cable in the Red Sea, where repair operations were delayed due to a combination of permit issues and regional political friction.
The Red Sea has also seen renewed disruptions. In September 2025, several key cables—including SMW4, IMEWE, and FALCON—were severed, resulting in slower internet traffic across Asia, the Middle East, and Europe. Microsoft reported delays in its Azure services, while governments and telecoms scrambled to reroute traffic. Permanent repairs are expected to take weeks or longer, once again underscoring the fragility of the world’s digital arteries.
Industry groups warn that these repeated disruptions reveal deeper structural issues. The European Subsea Cables Association (ESCA) and the International Marine Contractors Association (IMCA) have raised concerns that regulatory hurdles, a shortage of skilled personnel, and a lack of readily deployable repair ships are leaving Europe vulnerable in the event of multiple simultaneous outages.
Emerging technologies may help alleviate some of these challenges. Researchers are advancing the use of distributed acoustic sensing (DAS), which can convert ordinary fiber-optic cables into sensors capable of detecting nearby ships, anchors, or tampering attempts in real time. These systems, still experimental, could reduce detection times and improve coordination for repairs.
Security Concerns and Geopolitical Stakes
Beyond accidental damage, subsea cables are increasingly a target of deliberate interference. Experts warn that sabotage could be used as a tool for economic or political leverage, particularly in conflict zones or contested waters. The combination of high strategic value and relative vulnerability has prompted several countries to classify cables as national security assets.
Japan, for instance, has proposed recognizing undersea cables as critical to national security. Furthermore, the government will subsidize NEC’s cable ships (worth USD 300 million) to ensure faster repairs and reduce dependency on foreign operators. Similarly, the European Union has proposed a fleet of emergency cable repair vessels and expanded surveillance measures to detect potential threats before they cause damage. In 2025, the EU went further, adopting a Joint Communication on cable security that calls for mapping, risk assessment, supply-chain protections, and the use of autonomous underwater vehicles for monitoring.
Recent incidents have underscored why these measures are urgent. Swedish authorities investigated suspected sabotage of a telecom cable near Gotland, while Finland filed criminal charges against the crew of the oil tanker Eagle S for dragging its anchor and damaging multiple subsea cables in the Baltic Sea, causing nearly USD 70 million in damage. NATO has responded by launching Baltic Sentry, a mission that will deploy frigates, patrol aircraft, and naval drones to deter hostile activity around subsea infrastructure.
In the UK, Parliament has launched an inquiry into subsea cable resilience, while the Joint Committee on National Security Strategy criticized the government for being “too timid” in addressing these vulnerabilities. Meanwhile, analysts and policymakers are increasingly calling for tighter rules on “untrusted” components in cable systems, echoing earlier debates over 5G supply chains.
These moves reflect a growing awareness that digital infrastructure, much like ports, airports, and energy grids, is a core component of national security and that protecting it requires vigilance against both accidents and deliberate threats.
The Oceanic Trench Forward
Expanding repair fleets, developing faster and more efficient repair methods, and enhancing surveillance and protection measures are all necessary steps to secure the subsea floor. Equally important is fostering international cooperation to ensure that, when a cable is cut, repair crews can act swiftly, unimpeded by bureaucracy or politics.
Protecting subsea cables is necessary to achieve economic stability, national security, and uninterrupted communication, pillars that define modern life. In a world “under pressure” above and below, safeguarding these hydrostatic lifelines has become an urgent and shared responsibility.
