UK and Norway Conduct North Atlantic Operation to Deter Russian Submarines

British and Norwegian militaries conducted a military operation lasting more than a month to deter Russian submarines suspected of malign activity in the North Atlantic, according to a statement released by the U.K. Military on April 9, 2026.

Defence Secretary John Healey announced on April 9, 2026, that the operation involved the use of a frigate, aircraft, and hundreds of personnel to monitor a Russian attack submarine and two spy submarines. These vessels were detected near undersea infrastructure located north of the United Kingdom.

The Russian vessels eventually left the area following the conclusion of the operation. In a statement delivered at 9 Downing Street in Westminster, Healey issued a direct warning to Russia regarding the security of maritime assets.

we see your activity over our cables and our pipelines and you should know that any attempt to damage them will not be tolerated and will have serious consequences

John Healey, UK Defence Secretary

The Lunna House Agreement

This operational cooperation is supported by the Lunna House Agreement, a landmark defence pact unveiled on December 4, 2025. The agreement was announced during a visit by Norwegian Prime Minister Jonas Støre to RAF Lossiemouth, where he met with UK Prime Minister Keir Starmer.

Named after the Shetland Isles headquarters of the Norwegian resistance during the Second World War, the agreement establishes a framework for the Royal Navy and the Royal Norwegian Navy to operate as a single, interchangeable force in the North Atlantic.

The pact was prompted by a reported 30 percent increase in Russian vessels threatening UK waters between December 2023 and December 2025. A primary component of the agreement is the creation of a joint fleet of Type-26 anti-submarine warfare frigates.

The combined fleet consists of at least 13 warships, including eight British and at least five Norwegian Type-26 frigates. These vessels are tasked with conducting coordinated patrols across the North Atlantic, with a specific focus on the strategic gap between the United Kingdom, Iceland, and Greenland.

Investment and Infrastructure

The naval cooperation is backed by a £10 billion deal signed in September 2025, which is the largest warship deal in British history. This investment is intended to support more than 4,000 high-skilled shipbuilding jobs within the United Kingdom.

Beyond frigates, the agreement includes the use of autonomous systems and collaboration on Sting Ray torpedoes. The U.K. Has also agreed to adopt Norwegian naval strike missiles as part of the expanded cooperation.

Operational monitoring is further supported by P-8 maritime patrol aircraft. In the weeks preceding December 4, 2025, these crews detected the Russian intelligence ship Yantar operating on the edge of UK waters north of Scotland.

Broader Strategic Context

Defence Secretary John Healey stated on April 9, 2026, that Russia remains the primary threat to the United Kingdom and its allies. He noted that Russian leadership likely intends for Western nations to be distracted by conflicts in the Middle East, stating, We will not take our eyes off Putin.

The U.K. Government has also highlighted the link between Russian activities in the North Atlantic and the conflict in Ukraine, asserting that Russia has provided Iran with drone parts and other support.

In addition to submarine deterrence, the U.K. Military expanded its focus in late March 2026. Officials announced they were prepared to seize ships suspected of being part of Russia’s shadow fleet, which transports oil in violation of international sanctions imposed due to the war in Ukraine.

Previously, British efforts had been limited to monitoring these vessels before they were boarded by French or U.S. Forces. However, as of April 9, 2026, Healey confirmed that the U.K. Is ready to take action against these vessels.