Denmark is evaluating the acquisition of the Boeing P-8 Poseidon, described as the world’s most advanced maritime patrol aircraft, to address critical blind spots in its Arctic and North Atlantic submarine surveillance. The move is part of a broader defence agreement aimed at modernising Danish maritime and aerial capacities to meet NATO obligations and counter growing geopolitical threats.
NATO pressure and Russian submarine activity push Denmark to act
Since summer 2023, Norway has been operating a fleet of five P-8 Poseidon aircraft, primarily tasked with tracking Russian submarines and conducting search-and-rescue missions in the Barents Sea and Norwegian Sea. According to Forsvarets Efterretningstjeneste (Danish Defence Intelligence Service), Russia actively monitors the GIUK gap (Greenland-Iceland-UK corridor), a strategic choke point for submarines moving from the Arctic into the Atlantic, with potential aims to sabotage undersea infrastructure.
In this context, Danish Defence Minister Troels Lund Poulsen has expressed interest in collaborating with Norway, potentially buying flight hours or co-investing in the P-8 programme. Although Poulsen has not confirmed details, he emphasised the importance of Nordic defence integration in light of current security challenges.
The capabilities of the P-8 Poseidon
The P-8 Poseidon, developed by Boeing, combines intelligence gathering, surveillance, and anti-submarine warfare in a single platform. Equipped with sonobuoys to detect submarines and armed with torpedoes, mines, and missiles, the aircraft is a “Swiss army knife” of underwater combat, according to Norwegian Air Force Colonel Hans Martin Steiro.
With a range of over 2,200 km and four hours of patrol time, the P-8 offers rapid and far-reaching capabilities unmatched by Denmark’s current fleet. Until now, submarine tracking in Danish waters has relied on frigates, inspection ships, and Challenger aircraft—none of which are optimally equipped for anti-submarine warfare. Plans to install towed sonar on frigates were approved in 2018, but implementation has only recently begun.
Existing weaknesses in Danish surveillance
Several defence reports have pointed out Denmark’s inability to meet NATO’s submarine surveillance standards, especially in the GIUK gap. Mechanical issues have often grounded Challenger aircraft, while ships cannot match the speed of fast-moving submarines. As a result, critical monitoring gaps have emerged in an area considered vital for both transatlantic supply routes and deterrence against Russian aggression.
A bipartisan agreement in June 2023 laid the foundation for a ten-year defence upgrade. In January 2025, the government allocated funds for three Arctic-class vessels and two long-range drones, but officials and military experts now argue that airborne submarine detection is essential.
Toward a stronger Nordic military cooperation
Norwegian Defence Minister Tore O. Sandvik did not comment directly on a possible P-8 sharing deal, but noted that Norway and Denmark already collaborate on F-35 maintenance and should further explore joint weapons systems and strategic capacities.
Colonel Steiro welcomed broader use of the P-8 among allied nations, stating that permanent presence in the GIUK corridor—whether Norwegian, British, German, or American—requires shared resources. “If you have a fast-moving submarine, a ship will never catch it. But a plane like the P-8 can,” he told DR during the Steadfast Defender 2024 NATO exercise.
Strategic value for NATO and Denmark
With tensions mounting in the North Atlantic, acquiring the P-8 Poseidon would not only strengthen Denmark’s Arctic presence but also reinforce its commitment to NATO’s upcoming capability goals. The aircraft’s ability to respond quickly and monitor vast maritime zones makes it a linchpin in a region where underwater infrastructure sabotage is a rising concern.
Whether Denmark chooses to purchase its own P-8s or lease capacity from Norway, the decision signals a strategic pivot toward high-tech, multinational defence solutions in the face of renewed Russian assertiveness in the Arctic seas.
