Under the new, multi-domain ‘Baltic Sentry’ activity, NATO’s Allied Command Operations (ACO) will aim to deter attempts by state or non-state actors to damage Baltic Sea CUI, according to a Supreme Headquarters Allied Powers Europe (SHAPE) statement released on 14 January.
NATO’s move follows a series of CUI-related incidents in the Baltic Sea since 2022. The most recent occurred on 25 December 2024, when the EstLink2 power cable and several nearby internet cables running on the seabed between Estonia and Finland were damaged.
In November 2024, an internet cable linking Sweden and Lithuania and a telecommunications cable connecting Finland and Germany were cut. In October 2023, again between Estonia and Finland, the BalticConnector gas pipeline and several communications cables were damaged.
In subsequent political and public debates, the damage caused in these three incidents has been attributed potentially to ship anchors being dragged along the seabed.
The first Baltic Sea CUI incident took place in September 2022, when two Nordstream gas pipelines were ruptured by explosions, off Denmark’s Bornholm island.
In the immediate wake of the EstLink2 incident, NATO Secretary General Mark Rutte said on social media that NATO would enhance its Baltic Sea military presence.
In the SHAPE statement, General Christopher Cavoli – Supreme Allied Commander Europe (SACEUR) – said “‘Baltic Sentry’ will deliver focused deterrence throughout the Baltic Sea and counter destabilizing acts like those observed last month. It is indicative of the alliance’s ability to rapidly respond to such destabilization, and shows the strength of our unity in the face of any challenge.”
Ships from NATO’s two North Atlantic-focused standing naval forces, Standing NATO Maritime Group 1 (SNMG1) and Standing NATO Mine Counter Measures Group 1 (SNMCMG1), will participate in ‘Baltic Sentry’.
NATO has been steadily building Baltic presence for some time, including to support and integrate with Finland and Sweden as new member states. SNMG1 and SNMCMG1 have increased their focus on the Baltic region to address the CUI threat and other regional risks. This has included participating in national naval exercises focused on CUI security, like the Finnish Navy’s ‘Freezing Winds 2024’ activity conducted in the eastern Baltic in November.
Seabed-based CUI networks include cables carrying communications, data, and electricity; pipelines transporting oil and gas; environmental and other monitoring sensors; infrastructure including wind- and wave-power generation facilities; and oceanographic/hydrographic research instrumentation. The Baltic Sea is dissected by various CUI networks, with these networks part of wider maritime sea lines of communication that are economically vital to regional countries.
In a statement on 14 January, NATO Allied Maritime Command (MARCOM) said “With increasing reliance on undersea cables and pipelines, protecting this critical infrastructure is a continuing priority for NATO.” “‘Baltic Sentry’ is a multi-domain vigilance activity aimed at increasing maritime situational awareness (MSA) in the Baltic Sea to deter and defend against attacks on CUI,” the statement added.
Under ACO, Joint Force Command Brunssum will lead ‘Baltic Sentry’, synchronising the multi-domain activities. MARCOM will co-ordinate enduring maritime presence activities throughout the Baltic region. Commander Task Force (CTF) Baltic, the German Navy’s newly established tactical maritime headquarters, will have tactical control of ships working under MARCOM command.
The MARCOM-based NATO Centre for Security of CUI (NMCSCUI) – established in June 2023 as an operational-level networking and knowledge centre for countering CUI threats – will provide support for ‘Baltic Sentry’ through assisting allies in decision-making and activity co-ordination relating to CUI protection and response. Decision-making assistance will include sharing information to help allies better understand the operating environment.
“NATO forces maintain persistent presence in the Baltic, conducting regular patrols and joint exercises to enhance readiness.”
“Allied warships, submarines, and aircraft, supported by advanced maritime surveillance technology, are continuously monitoring waters throughout the region.”
“‘Baltic Sentry’ will enhance our regional MSA, which is integral for the alliance to deter and defend against … destabilizing acts. NATO’s primary role is to help understand the environment and identify vessels engaging in suspicious behaviour. This work will occur in close co-ordination with our regional allies to assist them in making decisions about how they would handle a suspicious vessel of interest.”
MARCOM spokesperson Commander Arlo Abrahamson.
Cdr Abrahamson explained that a wide range of military capabilities will be employed in support of ‘Baltic Sentry’, including ships, submarines, maritime patrol aircraft, satellites and radars, and uncrewed systems.
The MARCOM statement noted that NATO broadly is also investing in various military technologies relevant to countering CUI threats, including uncrewed underwater vehicles (UUVs), advanced sensors such as specialised sonar systems, and artificial intelligence.
“Securing CUI remains a national responsibility of allies: however, NATO is taking active steps to better support allies in enhancing CUI security.” Cdr Abrahamson.
‘Baltic Sentry’ has been announced on the same day that the Baltic Sea NATO Allies held a summit in Helsinki, Finland, the focus of which is also on Baltic security and CUI protection.
