Russia’s Shadow Fleet in the Baltic Sea
(By Anna Maria Flausino/JBANC)
It was not a merry Christmas for Estonian and Finnish government officials when, on December 25, 2024, the Estlink-2 power cable, which transmits energy from Finland to Estonia across the Baltic Sea, went down. The culprit of this particular incident is suspected to be a Russian vessel from their shadow fleet, a covert network of ships used to evade sanctions and conduct gray zone operations, such as undersea sabotage. The ship dragged its anchor for nearly a hundred kilometers along the seabed. Finland and Estonia acted swiftly, launching an immediate investigation.
The Baltic Sea has been the target of numerous acts of underwater infrastructure damage, with at least 11 reported incidents of undersea infrastructure damage since October 2023. The most recent incident occurred on January 26, 2025, when an underwater fiber optic cable connecting Sweden and Latvia was damaged. The vessel was seized and investigated by Swedish and Latvian authorities, who discovered that the Malta-flagged vessel departed from a Russian port a couple of days earlier. Most incidents of underwater sabotage are believed to have been caused by Russia’s shadow fleet, an aging tanker fleet with uncertain ownership that transports Russian oil to circumvent Western sanctions. There have also been reports of damage caused by Chinese vessels, a known Russian ally and ideological adversary of the West.
Beneath the surface, along the seafloor, run hundreds of kilometers of energy pipelines, telecommunications, and power cables. This critical undersea infrastructure is vital in trade, data transfer, energy security, and overall economic stability in Europe. These crucial undersea cables are particularly vulnerable to damage from anchors, fishing activities, earthquakes, and other natural disasters. These vulnerabilities have become a geopolitical flashpoint, as cable cutting by Russia’s shadow fleet follows a pattern of rhetoric and hybrid attacks that seek to undermine the sovereignty of the Baltic states. Having achieved their long-term ambitions to become NATO members in 2004, the Baltic states are a bulwark against renewed Russian imperial ambitions on NATO’s Eastern Flank. Challenges to NATO’s resolve in the form of hybrid attacks have become commonplace, with the Baltic Sea increasingly targeted by acts of underwater infrastructure sabotage.
Strategic Implications and Regional Response:
Most incidents of sabotage have not caused immediate irreparable harm to the Baltic States. However, the damage has significant and pressing strategic implications for NATO, the EU, and the broader Baltic Sea region. For one, there is a critical infrastructure vulnerability as undersea cables and pipelines carry internet traffic, military communications, and energy. The nature of the underwater cables and pipelines makes them difficult to monitor and protect, making them an ideal target for indiscriminate hybrid operations. Additionally, the sabotage may be intended to test NATO and sow doubt about its ability to deter or respond to indirect threats, therefore forcing NATO to adapt its deterrence posture. Finally, allies now recognize that traditional deterrence must be expanded to include subsea warfare capabilities to maintain operational readiness.
NATO, the JEF (Joint Expeditionary Force), and EU have launched initiatives to address security gaps in the Baltic Sea. One initiative launched during the Summit of Baltic Sea NATO Allies in Helsinki was the Baltic Sentry, a multi-domain NATO operation designed to protect critical undersea infrastructure in the Baltic Sea. It involves coordinated patrols using naval vessels, surveillance aircraft, as well as legal measures like vessel inspections and sanctions against actors linked to Russia’s shadow fleet.
In addition to the Baltic Sentry, NATO’s Task Force X operates a cutting-edge technological arm of Operation Baltic Sentry, deploying drones and robotic systems, both underwater and in the air, to scan the seabed for suspicious activity. By combining military assets with commercial technologies, Task Force X fills gaps and enables real-time anomaly detection, strengthening NATO’s hybrid defense posture and showcasing a new model of innovation-led deterrence in contested maritime domains.
Complementary to NATO’s efforts, the JEF activated the response option Nordic Warden in July 2024, coordinating the efforts of ten JEF nations, including the Baltic states and the UK. The operation involved 28 ships and 6 aircraft monitoring 33 vessels of interest in the Baltic Sea. These actions reflect a broader commitment by regional partners to interoperability and joint responses to Article 5 challenges.
The European Union has also taken initiative in responding to the undersea sabotage through its Action Plan on Cable Security. The plan includes establishing a regional surveillance hub, launching a drone-based monitoring program, and developing a fleet of emergency repair vessels. It is designed to complement NATO efforts, such as the Baltic Sentry, while reinforcing civil-military coordination within the EU. Additionally, the EU pledged to hold accountable those responsible actors, particularly those linked to Russia’s shadow fleet, through sanctions, joint investigations, and increased maritime oversight.
The repeated sabotage of undersea cables in the Baltic Sea highlights a troubling evolution in Russian hybrid warfare aimed at undermining NATO’s unity and the sovereignty of its Baltic members without crossing the threshold into open conflict. While the physical damage has so far been contained, the strategic implications are profound: critical infrastructure remains vulnerable, and NATO’s traditional deterrence strategies must adapt to address threats beneath the waves. The coordinated responses through Baltic Sentry, Task Force X, JEF, and the EU’s Action Plan demonstrate a growing recognition that defending undersea networks requires integrated, multi-domain efforts combining military, technological, and civilian tools. Yet, as this new front in the conflict unfolds, sustaining political will, especially continued U.S. support, will be vital to ensuring that NATO can effectively deter further attacks and uphold security across this strategically important region.
Image Source: Joint Expeditionary Forces
Link: https://jefnations.org/2025/05/02/baltic-express-shows-the-jef-at-its-most-cohesive/
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