Britain and Norway have launched new joint naval patrols aimed at protecting undersea cables from Russia, with a combined fleet of at least 13 warships safeguarding critical infrastructure in the North Atlantic, officials said. The announcement follows discussions in December between UK Prime Minister Keir Starmer and Norwegian Prime Minister Jonas Gahr Støre on defense cooperation.

British Defence Secretary John Healey said on Thursday that the operation was designed to deter Russian submarines suspected of “malign activity” near undersea infrastructure north of the UK. A frigate, aircraft, and hundreds of personnel monitored a Russian attack submarine and two spy vessels during an operation lasting more than a month. Healey said the Russian ships eventually left the area.

His message to Moscow was clear: “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.” Healey emphasized that while global attention is focused on conflicts in the Middle East, Russia remains the main threat to the UK and its allies.

British officials have highlighted the overlap between Russia’s support for Iran and its ongoing war in Ukraine. Tehran has provided Moscow with Shahed drones, which are now also manufactured in Russia under the designation Geran. Healey said, “Putin would want us to be distracted by the Middle East. We will not take our eyes off Putin.”

The UK has also prepared to seize ships suspected of being part of Russia’s “shadow fleet,” a flotilla of old oil tankers of unclear ownership designed to bypass international sanctions imposed over Moscow’s 2022 invasion of Ukraine. Previously, the UK only assisted France and the US in monitoring such vessels. Healey said, “We are ready to take action” against these ships.

Norwegian Defence Minister Tore O. Sandvik, who signed the joint naval agreement with Healey, said the patrols allow both countries to “defend themselves together.” The deployment builds on a £10 billion (€11 billion) deal for Norway to purchase at least five British-made frigates, which, together with eight British ships, will operate along NATO’s northern flank.

Russian naval activity near UK waters has reportedly risen by 30 percent over the past two years. NATO officials have also warned that attacks on undersea cables are among the “most active threats” to Western infrastructure. Acting Assistant Secretary General for Innovation, Hybrid, and Cyber, James Appathurai, said recent incidents in the Baltic Sea and elsewhere reflect Russia’s long-term undersea program, which includes research ships, submarines, unmanned vehicles, divers, and explosives targeting communications and energy pipelines.

The new UK-Norway patrols signal a heightened focus on securing vital maritime infrastructure amid rising geopolitical tensions and increasing Russian naval operations in European waters.