The UK government is preparing to announce the launch of a new maritime defence alliance with key European partners. The initiative aims to strengthen collective security in the North Atlantic, the North Sea, and the Baltic Sea amid growing submarine and hybrid threats from Russia.
According to sources in the UK Ministry of Defence, the alliance will focus on joint patrols, anti-submarine warfare, protection of critical underwater infrastructure (cables and pipelines), and countering Russia’s “shadow fleet.” It will build on existing cooperation frameworks, such as the bilateral pact with Norway (the Lunna House Agreement of 2025), the Atlantic Bastion programme, and the Joint Expeditionary Force (JEF) format, which brings together the UK with Nordic and Baltic states.
Norway, Denmark, Sweden, Finland, the Baltic states, and potentially Poland and the Netherlands are expected to join the alliance. Key objectives include:
Joint tracking and shadowing of Russian submarines;
Protection of underwater communications cables and energy infrastructure from sabotage;
Coordination against hybrid threats in the maritime domain;
Increasing the number of joint exercises and maintaining a permanent fleet presence in key areas.
The new maritime alliance is seen as an important complement to NATO efforts, particularly given uncertainty over the future of the American contribution to European security. The UK is positioning itself as Europe’s leading maritime power, capable of “filling the gaps” in anti-submarine defence and intelligence.
Experts note that the initiative reflects a broader trend of recent years: following Russia’s full-scale invasion of Ukraine, European nations have significantly intensified maritime security cooperation. Attention is being paid to NATO’s Northern Flank and the Baltic region, where the risk of sabotage against critical infrastructure is assessed as high.
An official announcement on the formation of the alliance is expected within the coming weeks, likely at an upcoming Joint Expeditionary Force summit or at a meeting of European defence ministers.