Baltic submarine cables cut again: Critical infrastructure at risk

On 25 December 2024, the Estlink 2 power cable between Finland and Estonia was severely damaged in an act described as sabotage by Finnish authorities. The incident is linked to the Eagle S tanker, allegedly part of the Russian shadow fleet, escalating geopolitical tension in the Baltic Sea. NATO and the Baltic nations have responded with increased security measures, highlighting the urgent need to protect critical undersea infrastructure in the face of growing threats.

Damage to Estlink 2: an act of sabotage

The damage to the Estlink 2 cable drastically reduced its power transmission capacity from 1,016 MW to just 358 MW. Finnish authorities have described the incident as "serious sabotage", focusing on the Eagle S tanker., a Cook Islands-flagged vessel suspected of being part of the Russian shadow fleet. According to investigators, the vessel reduced its speed by 25% just before crossing the cable, suggesting it may have used its anchor to cause the damage.

The Eagle S was seized by Finnish police and was carrying 35,000 tonnes of unleaded petrol. This highlights the strategic use of ageing vessels with opaque ownership structures in surveillance activities and possible sabotage, increasing tension in the region.

Response from NATO and the Baltic countries

The sabotage of Estlink 2 is not an isolated case. NATO and the Baltic nations have stepped up naval patrols in the Baltic Sea to protect critical infrastructure. Estonia, for example, has launched specific operations to protect its submarine cables and has strengthened its collaboration with neighbouring countries on maritime security.

Previous incidents, such as damage to the Nord Stream gas pipelines, have led to a more forceful response from Europe. These measures include advanced underwater surveillance networks, rapid response protocols and a coordinated approach to monitoring suspicious vessels. The increased military presence reflects the strategic importance of protecting vital connections in the region.

Russia's shadow fleet: a constant threat

Russia's so-called shadow fleet, made up of ageing vessels with opaque ownership, has emerged as a key player in maritime security challenges. In addition to facilitating the evasion of international sanctions, this fleet is linked to sabotage and espionage activities near critical infrastructure. In the case of the Eagle S, its suspicious behaviour has renewed fears about the use of these vessels as tools of destabilization.

The Baltic and Nordic nations have responded by stepping up inspections of these ships and pushing for additional sanctions. The European Union is considering new measures to restrict the activities of this fleet, which not only threatens energy security but also poses significant environmental risks due to its poor maintenance standards.

Advances in underwater surveillance

In response to these incidents, Europe is significantly improving its underwater monitoring capabilities. NATO and the EU are developing advanced sensor networks and autonomous underwater vehicles (AUVs) to detect and prevent sabotage. These systems enable real-time monitoring of submarine cables and can identify suspicious activities near critical assets.

Finland has accelerated the deployment of underwater drones and sonar technology following the damage to Estlink 2. In addition, Estonia has adopted AI-powered tools to analyse vessel behaviour patterns, such as the suspicious slowdowns that preceded the Eagle S incident. These innovations are crucial to anticipating potential threats and strengthening security in the Baltic Sea.

Critical infrastructure: a geopolitical target

The Baltic Sea's submarine infrastructure has become a strategic target in the context of geopolitical tensions. Power and communication cables are essential to the economic and military stability of the region, making them vulnerable to attack. This sabotage of Estlink 2 underscores how modern conflicts extend beyond traditional borders into the systems that sustain modern societies.

Maritime security has become a priority for European nations, which are now seeking to protect their underwater assets with more integrated and sophisticated strategies. From increasing international cooperation to strengthening rapid response protocols, countries in the region are showing a renewed commitment to defending their critical infrastructure against emerging threats.

A future of surveillance and resilience

The sabotage of Estlink 2 highlights the need for proactive measures to protect submarine infrastructure in an increasingly interconnected world. As geopolitical tensions escalate, Europe must maintain a constant focus on maritime security and technological development to counter new threats.

International collaboration will be key to addressing this problem. By combining technological advances with clear political strategies, Europe can ensure stability and security in the Baltic Sea. These incidents also highlight how critical infrastructure is at the heart of modern conflicts, demanding rapid and coordinated responses to minimise the impact of future attacks.

The path to resilience is set, but constant vigilance will be essential to protect the foundations of the region's economies and societies in the face of increasingly sophisticated challenges.