NATO Allies and other European nations are working to increase security of undersea cables and other infrastructure in the Baltic Sea after what they described as multiple acts of sabotage.
The Alliance announced in January 2025 that it is launching Baltic Sentry, a new mission to protect undersea cables in the region. Baltic Sentry will use frigates, maritime patrol aircraft and a fleet of naval drones to provide enhanced surveillance and deterrence, The Associated Press reported.
“Across the Alliance, we have seen elements of a campaign to destabilize our societies through cyberattacks, assassination attempts and sabotage, including possible sabotage of undersea cables in the Baltic Sea,” NATO Secretary-General Mark Rutte said.
Traficom, Finland’s transport and communications agency, discovered in December 2024 that several power and communications cables connecting Finland to neighboring countries had been damaged. Finnish authorities seized a Russia-affiliated vessel they believed carved a 96.5-kilometer-long drag mark on the sea floor in the Gulf of Finland, damaging the Estlink 2 electricity cable. The Eagle S oil tanker is registered in the Cook Islands in the South Pacific and was sailing from St. Petersburg, Russia, to Port Said, Egypt, according to news reports. The tanker crossed the Estlink 2 cable between Estonia and Finland on Christmas morning, at the same time when Finland said the power outage occurred, a Reuters review of MarineTraffic ship tracking data showed.
The Finnish government believes the vessel is part of Russia’s “shadow fleet” of ships with uncertain ownership used to evade Western oil sanctions imposed over the war in Ukraine. The investigation is ongoing.
“When a ship drags anchors along the seabed a long way, it can’t go unnoticed,” Estonia’s justice minister Liisa Pakosta told Reuters. She said it is time to update centuries-old maritime law to prohibit damage to underwater infrastructure. “The situation that is now at the Baltic Sea, where the anchors have been dropping several times in a row … it can’t be by accident. We think that it is a good idea to look over also the international law to make these investigations [run] more smoothly.”
Cable ruptures are usually accidental, but governments of several European countries have expressed alarm at what they believe is a pattern of deliberate sabotage since Russia’s 2022 unprovoked invasion of Ukraine. Ten Baltic Sea cables have been damaged since 2023, affecting Estonia, Finland, Germany, Lithuania and Sweden, The Associated Press (AP) reported.
In November 2024, representatives from Denmark, Finland, Germany and Sweden investigated a Chinese bulk carrier after two undersea fiberoptic cables in the Baltic were severed after the vessel left a Russian port. In October 2023, a subsea gas pipeline linking Finland and Estonia was severed by what Finnish investigators determined was a Chinese container ship dragging its anchor.
“Recent Baltic Sea sabotage attempts are not isolated incidents; they form a deliberate pattern aimed at damaging our digital and energy infrastructure,” European Union foreign policy head Kaja Kallas said in an interview with German newspaper Die Welt, according to The Hill.
NATO announced it will enhance its military presence in the Baltic. The Alliance established a Maritime Centre for the Security of Critical Undersea Infrastructure within NATO’s maritime command to improve information sharing and coordination among Allies. The center’s Critical Undersea Infrastructure Network held its first meeting in May 2024, bringing together stakeholders from government and industry to discuss how to use innovative technology including sea drones, sensors and artificial intelligence to enhance security. In September 2024, the U.S. joined more than 40 nations agreeing to principles aimed at enhancing security of undersea cables and related infrastructure, including transparency in provider selection, route planning to avoid damage to cables and adherence to domestic and international laws.
Sweden, NATO’s newest member, said it will contribute up to three warships and a surveillance aircraft to the effort, according to the AP. In addition, the country’s coast guard will contribute four ships to monitor the Baltic, with another seven vessels on standby.
“The increasing dependency of our societies on undersea infrastructure means we need to do more to enhance their security,” former NATO Secretary-General Jens Stoltenberg told attendees. “NATO is well placed to take on a greater role, given our Allies’ unique military capabilities, vast intelligence network and operational expertise.”
A 10-nation coalition, led by the United Kingdom, is using artificial intelligence to track Russia’s shadow fleet. The Nordic Warden operation aggregates and evaluates data from multiple sources, including an automatic identification system, which tracks vessels in real time. Potential threats are communicated to NATO Allies and Partners.
“Nordic Warden will help protect against both deliberate acts of sabotage as well as cases of extreme negligence, which we have seen cause damage to underwater cables,” U.K. Defence Secretary John Healey said in a news release. “Harnessing the power of AI, this U.K.-led system is a major innovation which allows us the unprecedented ability to monitor large areas of the sea with a comparatively small number of resources, helping us stay secure at home and strong abroad.”