Why subsea infrastructure has become a hybrid-warfare target
Subsea cables carry the majority of global data traffic while pipelines and power links transport energy across borders. Damage to any segment can disrupt markets and communications for days or weeks. The 2022 Nord Stream explosions demonstrated that deliberate interference is feasible and difficult to attribute quickly. Similar incidents near the Arctic and Taiwan have prompted NATO members and private operators to reassess decades of limited oversight.
Katja Bego of Chatham House told CNBC that the threat environment changed after 2022, moving an issue long treated as routine maintenance into the realm of national security. She noted that artificial intelligence, drones and autonomous systems now enable new forms of seabed surveillance that were previously impractical. The term hybrid warfare covers cyber attacks, energy sabotage, disinformation and economic pressure, with or without conventional forces. Bego stated that the changing threat landscape brought the topic to the fore. At the same time, rapid progress in artificial intelligence, drones and autonomous technology makes new approaches to underwater surveillance possible. The entire economy depends on these cables, she added, describing the maritime domain as the next logical theatre after the widespread use of drones in the Russia-Ukraine war showed how remote autonomous systems can alter warfare.
More than 1.5 million kilometres of subsea communication cables are in service worldwide as of early 2026, according to TeleGeography. In addition to telecom cables and oil-and-gas pipelines, a growing network of subsea power cables now links electricity markets and brings power from offshore wind farms to shore. The combination of these assets and the demonstrated vulnerability of the Nord Stream pipelines has shifted government attention to previously neglected seabed risks.
How companies are adapting to the underwater domain
Italian shipbuilder Fincantieri announced in July plans to acquire majority stakes in four specialist firms for roughly 600 million euros. The move expands its reach into underwater and surface drones, seabed mapping and subsea communications. Chief executive Pierroberto Folgiero described subsea telecommunications as the true catalyst for a new ecosystem in which surface vessels act as mother ships coordinating fleets of autonomous vehicles. The company is drawing on more than a century of submarine experience to move from what Folgiero calls the conventional underwater world to a non-conventional one that includes smaller submarines, drones and underwater telecommunications.
German firm Euroatlas has developed the GrayShark autonomous underwater vehicle. It can be programmed to reach a designated area, avoid obstacles and execute missions without continuous human control. Director of strategy Verineia Codrean said the vehicle can detect anomalies such as suspected mines, report them and await operator instructions. The company has signed contracts worth more than 100 million euros with unnamed European navies. A hydrogen-fuel-cell version is under development for up to 16 weeks of underwater endurance or 8 000 nautical miles, although this capability has not yet been demonstrated underwater. Codrean stressed that the vehicles are unarmed and their missions centre on surveillance, detection and deterrence.
Other major defence groups, including France’s Thales, have also expanded into sonar, anti-submarine warfare, mine detection and autonomous underwater systems as both large and small firms seek a role in the emerging seabed market.
What autonomous systems can and cannot achieve
Proponents argue that fleets of autonomous vehicles offer a scalable way to patrol vast ocean areas where crewed ships and submarines are too few and too expensive. Codrean emphasised that continuous coverage of every kilometre remains impossible, so priority must be given to high-value corridors. The vehicles are not armed; their roles focus on surveillance, detection and deterrence. She described the problem as one of scale: frigates, submarines and maritime patrol aircraft are too costly and too scarce to maintain constant presence over the enormous areas where cables, pipelines and other strategic assets lie. From a mathematical standpoint, crewed assets cannot be everywhere problems appear, whether sabotage or hostile submarine movement.
Bego cautioned that underwater autonomy faces steeper technical barriers than aerial drones. Limited visibility, difficult communications and the absence of reliable underwater data links mean progress is slower than in Ukraine. She described current systems as useful mainly for signalling presence and gathering basic awareness rather than providing comprehensive defence. Codrean noted that counter-AUV missions are already emerging, aimed at detecting, tracking and identifying autonomous vehicles operated by other states. Because adversaries are also building AUVs, forces must be able to distinguish friendly NATO or allied vehicles from others, raising the prospect of machine-versus-machine encounters. She does not expect autonomous vehicles to replace crewed submarines and warships entirely; instead, navies will increasingly combine manned and unmanned systems, making interoperability more important.
Who pays for protection and who is responsible
Most subsea cables and pipelines are owned or operated by private companies. Routine repairs have traditionally been a commercial matter. Heightened sabotage risks now draw governments into the discussion. Bego said officials are pressing for stronger security measures, including deeper burial of cables and added sensors, yet cost allocation and liability remain unresolved. Closer public-private cooperation is expected rather than regulation alone. Russia and China are also reported to be increasing spending on underwater capabilities, adding to the competitive dynamic on both sides of the Atlantic. Bego observed a huge surge in drone investment driven by these concerns.
Despite the spending, a fundamental problem persists: no one can realistically protect every kilometre of seabed infrastructure. Bego noted that no NATO representative would claim the ability to safeguard a network exceeding one million kilometres. The responsibility for protecting this infrastructure is therefore unclear, and the outcome will require much closer cooperation between governments and infrastructure owners.
Frequently asked questions
What is the total length of operational subsea cables?
TeleGeography reports more than 1.5 million kilometres of subsea communication cables in service worldwide as of early 2026.
Which incident raised awareness of seabed vulnerability?
The September 2022 explosions that ruptured the Nord Stream gas pipelines under the Baltic Sea demonstrated deliberate sabotage of critical subsea infrastructure.
Which companies are investing in underwater drones?
Fincantieri is acquiring four specialist firms for about 600 million euros, while Euroatlas has secured more than 100 million euros in GrayShark contracts with European navies.
Can autonomous vehicles replace crewed submarines?
Experts expect a mixed fleet approach. Autonomous systems will handle routine patrols, but crewed assets will remain necessary for complex interventions.
Who bears the cost of extra security measures?
Responsibility is still being negotiated. Private operators traditionally handle maintenance, yet governments are increasingly involved in setting standards and sharing costs for sabotage protection.
