Underwater naval operations and shallow sea facilities in Europe experiencing targeted assaults
Europe finds itself in a precarious position, with the most extensive network of subsea connections in the world. The strategically important Baltic Sea infrastructure plays a crucial role in this complex web, but it also makes Europe vulnerable to attacks.
Since 2022, Russia has been reported to have created a "ghost fleet" of over 400 old, rusty oil tankers, known for exporting oil and, more concerningly, sabotaging undersea cables. This covert operation has raised concerns among European leaders and intelligence agencies.
The EU must prioritise mapping its existing and planned undersea infrastructure to identify the most critical and vulnerable systems. Failing to act decisively today exposes Europe to far greater threats tomorrow.
In an attempt to address this issue, European leaders and intelligence agencies must be more assertive in deterring threats to critical infrastructure. They can hold those responsible accountable through effective attribution, such as forensic analysis.
The large-scale invasion of Ukraine in 2022 is believed to be the starting point for Russia's targeting of critical European undersea infrastructure. Among the targets were the Nord Stream 1 and Nord Stream 2 gas pipelines.
In response, the EU introduced its own Action Plan for Subsea Cable Security in February 2025. Additionally, NATO launched Baltic Sentry in January 2025, a mission aimed at strengthening maritime presence and surveillance in the Baltic Sea.
However, the threat is not limited to Russia. China unveiled a new subsea device in March 2023, capable of cutting undersea cables up to a depth of 4,000 meters. Given the average depths of the Baltic Sea (52.3 meters) and the North Sea (95 meters), these bodies of water are vulnerable to undersea cable severance.
Europe can increase costs for hostile actors through stricter sanctions that eliminate current loopholes and prevent Moscow from maintaining significant revenues. Moreover, Baltic Sea states can impose stricter controls on Russian oil shipments by declaring a "special period" and temporarily suspending certain maritime laws.
Disrupting the network of undersea cables in Europe would make daily activities almost impossible for European citizens and businesses. More than 60% of Russia's seaborne crude oil exports transit through the Baltic Sea, and these cables transmit around $10,000 billion in daily financial transactions, as well as 97% of global internet traffic and a significant portion of government communications.
As the threat of undersea cable sabotage continues to grow, Europe should mandate companies to develop backup systems for undersea cables and better utilise existing surveillance tools. Strengthening international intelligence cooperation is also key to addressing this threat.
Unfortunately, the identity of the person or organisation that acquired the "Ghost Fleet" of 400 old oil tankers remains unknown. This lack of information underscores the need for increased vigilance and cooperation among European nations.
