Greenland Is a Homeland Security Issue for All NATO Allies

The 2026 U.S. National Defense Strategy mentions access to Greenland as essential for the defense of the U.S. homeland. However, insufficient surveillance and response capabilities in and around Greenland put all NATO allies at risk. Drawing on a recent wargame, this op-ed identifies capabilities the US and its allies should invest in to address this risk.

Insufficient allied military surveillance and response infrastructure along the coast of east Greenland allows Russia to pose a credible and complex nuclear threat against both the U.S. homeland and the majority of NATO. As a relatively weak power in economic and conventional terms, Russia’s desire to challenge NATO security interests depends on its ability to field nuclear capabilities that can reach U.S. and European territory. Early warning and missile defense equipment on Greenland is crucial to detecting Russian land-based intercontinental ballistic missiles (ICBMs), which Moscow would most likely launch northward over the Arctic, the shortest and fastest route.

Most of Russia’s submarine fleet is located by the Barents Sea near northern Norway. Russia’s nuclear-capable ballistic missile submarines (SSBNs) are a formidable threat. They provide a survivable second-strike capability, with ballistic missiles capable of reaching the U.S. homeland from patrol areas in the Arctic and the North Atlantic. They can move to launch position in Arctic waters such as the Queen Victoria Sea, allowing missiles to follow a polar trajectory to North America and avoid dense radar coverage. However, equally worrying are Russia’s nuclear-powered guided missile submarines (SSGNs) and attack submarines (SSNs). The Yasen- and Oscar II–class SSGNs are designed for large, long-range, nuclear-capable cruise missile salvos and can also threaten the North American mainland from afar.

Beyond the missile threat, these submarines are able to remain hidden, penetrate defended areas, and deliver surprise strikes with strategic implications. Russian SSNs are quieter and smaller than SSGNs. They are well-suited for covert nuclear delivery using nuclear-capable cruise missiles, particularly at shorter ranges. This means that they can reach targets in Europe or even North America provided they exit their Barents Sea bases and reach the Atlantic Ocean undetected.

In November 2025, Hudson Institute’s Center for Defense Concepts and Technology conducted an Arctic wargame set on the transit route of Russian submarines from the Barents Sea through the Norwegian Sea and the GIUK gap to the Atlantic Ocean. Two out of three teams managed to sink one SSN each, out of a total of six Russian submarines. This means the majority of Russian submarines were able to proceed through to the Atlantic Ocean undetected. From here the subs are hard to detect and have a good chance of reaching launch positions along the North American coastline. The teams that did manage to sink a Russian sub were equipped with drones capable of submarine hunting in quantities that are not currently available to NATO forces.

Nuclear-powered submarines are survivable because they are difficult to locate in vast oceans and can remain submerged for extended periods. Attack submarines routinely deploy forward to patrol choke points, monitor adversary naval movements, escort carrier groups, and conduct intelligence missions. Russia’s doctrine explicitly includes the option to use dual-capable precision missiles as part of its strategic nuclear forces. So Russia can choose to load nuclear warheads onto smaller, faster SSNs to gain the upper hand in a crisis involving Europe or North America. At present, Russian subs have ample opportunities to hide in areas with little surveillance, such as under floating sea ice in the fjords of east Greenland.

NATO does not currently have the means to counter the Russian submarine challenge. Peacetime submarine detection and tracking require fielding interoperable submarines, maritime patrol aircraft, and uncrewed systems, all of which the U.S., the UK and Norway already have. But the network is not dense or reliable enough across the submarine transit route from the Barents Sea to the GIUK gap. Another issue NATO faces is a lack of polar-capable assets, which are essential for detection and mobility in this region. Priority investments include:

These capabilities would help NATO establish a common tracking picture with cross-domain security guards that would greatly strengthen deterrence of Russian submarine activity in ice-filled waters during both war and peacetime.

Further NATO investments in layered sensing, crewed and uncrewed teaming, and resilient logistics and space systems, backed by industrial capacity and political unity should also be priorities. By phasing investments, exercising smartly, and managing legal and political frictions, NATO allies can raise the risks and costs for opponents contemplating coercion or conflict in the Arctic while preserving freedom of navigation and preventing full-scale warfare. Only by making these investments can NATO change the risk and cost calculus of opponents contemplating expanding their military force posture in the Arctic.

Liselotte Odgaard is a senior fellow at Hudson Institute.