The story of submarine infrastructure is a hidden narrative of global connectivity, beginning with a simple experiment and evolving into a vast, vital network that now faces profound security and legal challenges.
The Genesis and Critical Scale of Subsea Assets
Submarine infrastructure was born in 1847 when German engineer Carl Wilhelm Siemens successfully tested a gutta percha-insulated telegraph cable under the Rhine. This proof of concept quickly led to major achievements, including the laying of a cable beneath the English Channel and the historic first transatlantic telegraph exchange in 1858. Siemens’s family name lives on in the vast multinational conglomerate he founded.
- Data Network: Today, this endeavor is immense, driven by the internet. There are approximately 870,000 miles of subsea fibre optic telecoms cabling, with a further 750,000 miles planned. These cable networks are the primary global data carriers, handling 95% of all data transmission and facilitating trillions of dollars of financial transactions daily.
- Energy and Economic Value: In addition to data, the seabed holds nearly 20,000 miles of active submarine oil and gas pipelines, with up to six times that amount anticipated, plus increasing numbers of cross-border electricity link cables. The overall value of all this kit is estimated to be at least hundreds of billions of dollars.
Security Risks and Geopolitical Tension
The sheer scale and critical function of this infrastructure make it a clear security target. While rational states are interested in its smooth operation, the risk of disruption by hostile state or non-state actors is very real, with disabling the internet viewed as a potentially crippling attack.
- Hybrid Warfare: The threat is being taken seriously at the highest levels. EU President von der Leyen has accused Russia of running a ’targeted grey zone campaign’ focused on subsea infrastructure disruption.
- Vulnerability of Shipping: The shipping industry, ironically responsible for laying these cables, also represents the most obvious means by which damage, whether negligent or malevolent, can be inflicted.
The Problem of Legal Jurisdiction
A recent court decision concerning the Eagle S tanker has exposed a critical gap in the international legal regime intended to protect subsea infrastructure, particularly outside of territorial waters.
- The Incident: Three officers from the Russia-linked tanker Eagle S were charged in Finland with aggravated criminal mischief and aggravated interference with telecommunications. This followed allegations that the vessel dragged its anchor for 90 km in the Baltic in late 2024, severing the Estlink2 energy cable between Finland and Estonia. The prosecution focused on negligence in windlass maintenance, not deliberate sabotage.
- Jurisdictional Ruling: The Helsinki District Court dismissed the charges by ruling that it lacked jurisdiction. The court found that because the alleged damage was caused by a Cook Islands-flagged ship, the power to prosecute rests with the flag state or the defendants’ native countries, even though the incident occurred in Finland’s Exclusive Economic Zone (EEZ).
- Legal Consequences: Shipping lawyers consulted on the matter believe this conclusion was the only one possible under the United Nations Convention of the Law of the Sea (UNCLOS). This principle effectively means that if a flag state chooses not to initiate action, no other state can. This is seen as creating a “green light for those who wish us harm,” though prosecutors have since launched an appeal against the ruling.
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Source: Lloyd’s List
