NATO’s maritime activities

 

 

• The Alliance Maritime Posture
• Strengthening NATO's maritime posture in response to Russia's war in Ukraine
• NATO's Standing Naval Forces
• Critical Undersea Infrastructure
• NATO's maritime operations and activities

 

The Alliance Maritime Posture

The maritime domain encompasses oceans and seas – including everything on, above and below the surface, in all directions. It forms a continuum with other operational domains (land, air, space and cyberspace).

The Alliance Maritime Posture describes NATO's capabilities and functions in the maritime domain, and how it uses its naval forces to support the Alliance's three core tasks: deterrence and defence, crisis prevention and management, and cooperative security.

NATO’s naval forces are composed of maritime forces, sensors and other capabilities that contribute to Allied security. The Alliance Maritime Posture relies on these forces to perform the following three functions:

Strategic function: The presence of maritime forces creates strategic and deterrent effects, including for assurance and messaging, and demonstrates NATO's intent to operate as required. The flexibility of maritime forces provides nearly instant availability of inherently tailorable force packages yielding a range of measured and viable political and military options.

Security function: NATO maintains a safe and secure maritime environment through a range of maritime security operations and activities. Maritime forces provide a ready and flexible mechanism with significant versatility for a broad range and scale of missions and tasks.

Warfighting function: In the event of a conflict, maritime forces can rapidly transition from low-intensity to high-intensity missions and tasks. Surface, sub-surface and above-surface capabilities and forces can work together to exercise sea denial or control, support reinforcement, protect assets, project power and support joint forces and joint effects.

 

Strengthening NATO's maritime posture in response to Russia's war in Ukraine

Since Russia's illegal annexation of Crimea in 2014, the Alliance has adapted and strengthened its deterrence and defence posture across all domains. In response to Russia's full-scale invasion of Ukraine in February 2022, NATO activated its Graduated Response Plans and deployed high-readiness elements of the NATO Response Force (NRF) for the first time in a deterrence and defence role – including the activation of the Standing Naval Forces as part of the NRF's Very High Readiness Joint Task Force (VJTF). In July 2024, the NRF was replaced by the NATO Force Model and the Allied Reaction Force (ARF), which continues to include maritime forces.

Since February 2022, NATO has stepped up its vigilance activities – including an increased presence of Allied aircraft carriers in the Baltic, Adriatic and Mediterranean Seas, and the deployment of multiple Carrier Strike Groups – to ensure appropriate strategic awareness and force readiness. By leveraging a deliberate rhythm of military activity across all geographic areas of the Alliance, as well as across all operational domains and functional areas, multi-carrier deployments demonstrate Allied resolve to protect NATO populations and defend every inch of Allied territory – including Allied territorial waters – at all times.

Through maritime exercises, NATO Allies and partners are maintaining and developing warfighting competencies, building interoperability between their forces as well as improving their overall combined maritime skills and readiness for all operations, international and national. Some areas and competencies being incorporated into exercises include: high-end warfighting capacities, such as the protection of sea lines of communication, rapid reinforcement, amphibious operations, anti-submarine warfare, land attack, deep-precision strike, and integrated air and missile defence; countering hybrid threats in the maritime domain; defending against threats in cyber space; and countering threats against carrier strike groups.

 

NATO's Standing Naval Forces

The Standing Naval Forces (SNF) are a core maritime capability of the Alliance and a centrepiece of its maritime posture. Under NATO operational control, they provide the Alliance with a continuous, credible and agile maritime capability that can be rapidly deployed in times of crisis or tension. The SNF are a multinational deterrent force that can respond rapidly to defend against any potential adversary, and contribute to crisis management, security cooperation with partners and maritime security. They carry out a programme of scheduled exercises, manoeuvres and port visits. They also conduct joint training exercises with NATO partners to enhance interoperability.

NATO's SNF consist of four groups: the Standing NATO Maritime Groups (SNMG1 and SNMG2) and the Standing NATO Mine Countermeasures Groups (SNMCMG1 and SNMCMG2). They operate in the Atlantic Ocean and in the Baltic, North, Mediterranean and Black Seas, covering the entire maritime area of responsibility of NATO.

SNMG1 and SNMG2

The Standing NATO Maritime Groups are multinational, integrated maritime forces made up of frigates or destroyers from various Allied countries, supported by a replenishment vessel. These vessels are permanently available to NATO to perform different tasks ranging from exercises to support of operations. They also help to establish Alliance presence, demonstrate solidarity, conduct routine diplomatic visits to different countries, support partner engagement and provide a variety of maritime military capabilities to ongoing operations.

SNMG1 and SNMG2 function according to the operational needs of the Alliance, therefore helping to maintain optimal flexibility.

As part of NATO's Standing Naval Forces, SNMG1 and SNMG2 fall under the authority of the Supreme Allied Commander Europe (SACEUR). In December 2012, Allied Maritime Command (MARCOM) became the operational hub for all Alliance maritime operations. As such, authority and operational command over the SNMGs are generally delegated to MARCOM.

Located in Northwood, United Kingdom, MARCOM also hosts the NATO Shipping Centre (NSC), which is the link between NATO and the merchant shipping community. Permanently manned by NATO, the NSC is the primary point of contact for the exchange of merchant shipping information between NATO's military authorities and the international shipping community. It also plays an important role in countering piracy.

The Standing Naval Force Atlantic, SNMG1's precursor, was activated in January 1968. The force was re-designated Standing NATO Maritime Group 1 in January 2005.

Standing Naval Force Mediterranean, SNMG2's precursor, was activated in 1992 in Italy. It deployed to the eastern Mediterranean Sea in support of Operation Active Endeavour, the precursor of Operation Sea Guardian. The force was re-designated Standing NATO Maritime Group 2 in January 2005.

SNMCMG1 and SNMCMG2

The Standing NATO Mine Countermeasures Groups – SNMCMG1 and SNMCMG2 – are multinational forces composed of minehunters and minesweepers that primarily engage in search and explosive ordnance disposal operations. They also conduct historical ordnance disposal operations to minimise the threat from mines dating back to the World Wars, thereby contributing to global navigation safety.

SNMCMG1 was formed in the Belgian port of Ostend on 11 May 1973 to ensure safety of navigation around the ports of the English Channel and northwest Europe. Originally called "Standing Naval Force Channel", its name was changed several times to reflect its expanding area of operation.

SNMCMG2 developed from an on-call force for the Mediterranean, which was created in 1969. It also evolved over time to reflect its new responsibilities.

SNMCMG2 and SNMCMG1 were both given their current names in 2006.

 

Critical Undersea Infrastructure

Undersea cables carry an estimated USD 10 trillion in transfers every day; two thirds of the world's oil and gas is either extracted at sea or transported by sea; and around 95 per cent of global data flows are transmitted through undersea cables. For NATO, the protection of critical undersea infrastructure – from pipelines to data and energy cables – is essential to security and defence because it is key to securing and protecting the prosperity of Allied societies.

NATO has been working to enhance the security of critical infrastructure for years. Following the sabotage of the Nord Stream pipeline in September 2022, Allies have stepped up their efforts to protect critical undersea infrastructure and their military presence in the Baltic Sea region specifically.

• In February 2023, NATO created a Critical Undersea Infrastructure Coordination Cell to support engagement between NATO Allies, partners and the private sector.
• The following month, NATO and the European Union launched the NATO-EU Task Force on the Resilience of Critical Infrastructure, which includes critical undersea infrastructure in its work.
• In May 2024, the Alliance established a new NATO Maritime Centre for the Security of Critical Undersea Infrastructure within Allied Maritime Command in the United Kingdom.
• In the same month, NATO also set up a new Critical Undersea Infrastructure Network for individual Allies, the private sector and other relevant actors to improve information sharing and explore ways to defend against threats to undersea infrastructure through the use of innovative technologies.
• In January 2025, NATO launched the Baltic Sentry maritime activity to strengthen the protection of critical infrastructure in the Baltic Sea.

These actions are improving coordination among Allies, partners and industry, helping them respond to growing threats against critical infrastructure.

 

NATO's maritime operations and activities

Building on the strength of its naval forces, NATO's maritime operations have demonstrated the Alliance's ability to achieve strategic objectives in vastly different contexts.

Baltic Sentry

NATO Allies have maintained a maritime presence in the Baltic Sea for decades, conducting regular patrols and joint exercises to ensure stability and freedom of navigation. Following increased acts of sabotage against critical undersea infrastructure, including pipelines and Internet cables, Allies agreed to enhance NATO’s presence in the Baltic Sea region and launched a multi-domain activity called Baltic Sentry in January 2025.

Baltic Sentry strengthens the protection of critical undersea infrastructure by deploying a range of assets, including frigates, maritime patrol aircraft and a small fleet of naval drones. NATO is working with Allies to integrate national surveillance assets, improving the ability to detect threats to critical undersea infrastructure and respond if required. The Alliance is also cooperating with industry to explore further ways to protect infrastructure and improve the resilience of underwater assets. 

Baltic Sentry is led by Allied Joint Force Command Brunssum (JFCBS), with Allied Maritime Command (MARCOM) playing a central role in the activity’s maritime domain. It falls under the overall command of the Supreme Allied Commander Europe.

Operation Sea Guardian

Operation Sea Guardian (OSG) maintains a safe and secure maritime environment in the Mediterranean Sea through three main tasks: maritime security capacity-building, situational awareness and counter-terrorism. The operation was launched in November 2016 as the successor to Operation Active Endeavour.  

Allies and partners can flexibly contribute to Operation Sea Guardian in different ways: through "direct support" by placing assets under NATO operational command, and "associated support" with assets that remain under national command. Operation Sea Guardian is under the operational command of Allied Maritime Command in Northwood, United Kingdom, which serves as the Alliance's hub for maritime security information sharing.

Every year, Operation Sea Guardian conducts five to six focused operations in specific areas of interest in the Mediterranean. These operations use sea, air, sub-sea and other assets to gather, develop and maintain an accurate picture of daily activity in different parts of the Mediterranean Sea. In this context, most focused operations conducted under Operation Sea Guardian also includes port visits to non-NATO countries.

As part of Operation Sea Guardian, NATO cooperates with partner countries and other international organisations. For example, Australia contributed to Operation Sea Guardian in 2022 with a maritime patrol aircraft flight.

Support to the refugee and migrant crisis in the Aegean Sea

NATO has contributed to international efforts to assist with the refugee and migrant crisis since February 2016. To that end, as part of the Alliance's Aegean Activity, NATO ships have been conducting reconnaissance, monitoring and surveillance of crossings within the Aegean, in cooperation with the Greek and Turkish coastguards and through the establishment of direct links with Frontex (the EU's border management agency). NATO ships help to cut the lines of illegal trafficking within the Aegean Sea while providing maritime situational awareness.