Estonia has sent a patrol vessel to guard its remaining Estlink 1 undersea power cable after the failure of Estlink 2, in a move that underscores rising concern over sabotage in the Baltic Sea. Nato also said it would increase its military presence in the region after a ship suspected of damaging the cable was boarded by Finnish authorities.
The patrol boat Raju set sail early on Friday, according to Estonian Defence Minister Hanno Pevkur. He said the vessel’s main task would be to make sure nothing happened to the remaining cable and to keep Estonia’s critical connection with Finland operational. Pevkur also said he believed Finland would join the operation.
The trigger for the response was the damage to Estlink 2, the 170km power link that supplies a major connection between the two countries. Estonia’s electricity supply has been dramatically reduced since the cable was shut down. Fingrid, Finland’s grid operator, said repairs could last until the end of July 2025.
Finnish authorities suspect the oil tanker Eagle S of damaging the cable. The Finnish coast guard boarded the ship and steered it into Finnish waters after its anchor was found missing. The European Union said the vessel was part of Russia’s shadow fleet and called the failure of the cable the latest in a series of suspected attacks on critical infrastructure.
The Kremlin declined to comment in detail, calling it a very narrow issue. Nato secretary-general Mark Rutte said the alliance would boost its presence in the Baltic, and Nato later said it remained vigilant and would provide further support. Estonia has not ruled out invoking Article 4 of the Nato treaty if it feels threatened.
The incident comes after several other disruptions in the Baltic region. In the previous month, two data cables were severed, and the Arelion and C-Lion 1 links both suffered damage. Earlier, a Chinese ship named Yi Peng 3 was suspected of dragging its anchor over underwater cables. In 2023, another Chinese vessel ruptured a gas pipeline between Finland and Estonia.
The wider strategic context is obvious. Estonia and Finland are both Nato members, and both sit on a vulnerable edge of the alliance where subsea infrastructure carries electricity, data and political symbolism. The damage to Estlink 2 is therefore not just a technical fault; it has become part of a pattern that European officials see as critical infrastructure under pressure.
Estonian Prime Minister Kristen Michal sought to reassure the public that back-up power systems were available, but he also acknowledged that it is impossible to protect every square metre of seabed at all times. That remark captures the tension at the heart of the response: governments can harden defences and increase patrols, but they cannot fully seal the vulnerable infrastructure running beneath the Baltic.
The immediate result is a militarised protective posture around a civilian power cable. The longer-term result may be more Nato presence, more patrols and more pressure on Europe to treat underwater infrastructure as a frontline security issue.
