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Baltic Sentry: NATO’s enhanced activity in the Baltic Sea

Piotr Szymański

On 14 January, a summit of NATO member states from the Baltic Sea region was held in Helsinki, attended by the NATO Secretary General and a Vice President of the European Commission. Other participants included the prime ministers of Denmark, Sweden, Poland, and Estonia, the German chancellor, and the presidents of Lithuania, Latvia, and Finland. The meeting was initiated by Finland and Estonia, whose undersea telecommunications cables and a power line in the Gulf of Finland were damaged in December 2024.

The summit was used to announce the launch of NATO’s enhanced vigilance activity to protect critical undersea infrastructure (‘Baltic Sentry’), planned since 30 December. The initiative seeks to enhance situational awareness and deter hostile activities. In a joint statement, participants highlighted ongoing efforts to establish an integrated regional picture on critical infrastructure, modernise this infrastructure, and develop rapid repair capacity. They also stressed the importance of new technologies for surveillance and tracking of suspicious vessels and undersea monitoring (in cooperation with the private sector), while pledging to actively share information and best practices. The leaders declared that any attack on their undersea infrastructure will be handled with resolve, and that robust set of measures targeting the so-called shadow fleet would be implemented.

The actions for protecting critical infrastructure, outlined in Helsinki, have the potential to mitigate the risk of increased attacks on undersea cables and pipelines. However, their effectiveness will rely on the detachment of sufficient military resources, the resolve of Baltic Allies to engage actively beyond their territorial waters, and closer multilateral cooperation.

Commentary

  • NATO’s decision to enhance activity in the Baltic Sea responds to an increase in hostile activities targeting critical undersea infrastructure owned by Finland, Sweden, Germany, Estonia and Lithuania. November and December 2024 witnessed two significant incidents involving anchor dragging along the seabed. Between 17 and 18 November, the China-flagged bulk carrier Yi Peng 3 damaged telecommunications cables linking Finland and Germany, as well as Sweden and Lithuania. On 25 December, the Cook Islands-flagged tanker Eagle S severed the undersea power line between Finland and Estonia (Estlink 2) and damaged four telecommunications cables. Earlier, in October 2023, a Hong Kong-flagged container ship damaged the Balticconnector undersea gas pipeline linking Finland and Estonia. Other hybrid activities in the Baltic Sea region include hazardous incidents involving the Russian Navy and Air Force, as well as GPS jamming. A persistent threat to maritime and environmental security is posed by the so-called shadow fleet, a group of ageing tankers transporting Russian oil in breach of sanctions. Enhancing energy infrastructure protection is critical for the Baltic states, particularly as they prepare to synchronise their electricity grids with the European system in February.
  • While the launch of Baltic Sentry will bolster critical infrastructure protection in the Baltic Sea, NATO’s measures have certain limitations. At present, the Alliance’s enhanced activity is not intended as a permanent operation, as initially proposed by Poland, which floated the idea of a navy policing mission. Instead, it is currently limited to a 90-day timeframe. Furthermore, the number of ships assigned to Baltic Sentry has not been officially disclosed, although media reports indicate that 10 vessels could be involved. This may reflect the challenges allies face in generating the necessary capabilities. Initially, the mission will involve Standing NATO Maritime Group One (SNMG 1), which has deployed a Dutch frigate to the Baltic Sea, and Standing NATO Mine Countermeasures Group One (SNMCMG 1) with a German minehunter and a Dutch hydrographic survey vessel. NATO activities will also include aerial monitoring of maritime areas and the use of unmanned underwater vehicles. Baltic Sentry is coordinated by the Commander Task Force-Baltic (CTF Baltic), a naval headquarters established in Rostock in October 2024, and supported by Operation Nordic Warden, launched at the start of the year. Carried out by the UK-led Joint Expeditionary Force (JEF), this operation involves an advanced system for tracking shadow fleet vessels.
  • During the summit, Finland’s response to recent incidents in the Gulf of Finland was highlighted as a model for addressing threats to critical infrastructure in the Baltic Sea, although its replication may prove challenging under different circumstances. The tanker Eagle S, suspected of damaging undersea cables, was first escorted by the Finnish Border Guard into Finland’s territorial waters. Special forces then boarded and seized the vessel. Following the identification of technical and safety deficiencies, Eagle S was detained, and its cargo seized. This decisive action, including the boarding operation, was partly facilitated by the cooperation of the tanker’s crew, who agreed to leave Finland’s exclusive economic zone and enter its territorial sea, falling under Finnish jurisdiction. However, NATO Allies must develop strategies to address incidents involving ships flying the flags of major powers that refuse to cooperate with law enforcement authorities. For instance, the bulk carrier Yi Peng 3 remained anchored in the Danish Straits for over a month under surveillance by Danish and German naval vessels but was ultimately not detained.