Greenland and Strategic North American Defense in the 21st Century
Abstract
Since the inauguration of the new administration in January 2025, nuclear modernization and missile defense have become major topics in national security discourse. Greenland has often stood at the center of this attention, with North American defense and rare earth elements frequently cited as the main factors. However, defense architecture is often nebulous and misunderstood and has not been thoroughly articulated in the context of recent U.S. political interests over the last year. Greenland’s role in North American defense additionally remains both legitimate and underexamined, where a complete understanding is vital for well-informed policy conversations.
Although the Golden Dome for America concept is often mentioned, its significance for Greenland’s changing role remains unclear. This article intends to address these gaps by exploring the two distinct, yet overlapping architectures of U.S. nuclear command, control, and communications (NC3), and missile defense that are presently supported by infrastructure in Greenland, followed by an explanation and comparative table of Greenland’s Cold War-era role vs. its role today. We conclude with additional thoughts about the challenges of unified military planning that converge in Greenland.
Introduction
Since the inauguration of U.S. President Donald J. Trump in January 2025, nuclear modernization and missile defense have become major topics in national security discourse. The 2025 National Security Strategy and 2026 National Defense Strategy asserted the need for a “modern nuclear deterrent [and] next-generation missile defenses.” Secretary of War Pete Hegseth issued a memo in February 2025 listing 17 high-priority missions for the Department of War (DoW) that were to be excluded from his goal of reducing the DoW’s budget by eight percent. Included among these were modernization of the nuclear enterprise, including nuclear weapons and nuclear command, control, and communications (NC3); homeland missile defense; and support for the Combatant Command missions of U.S. Northern Command (USNORTHCOM), U.S. Strategic Command (USSTRATCOM), and U.S. Space Command (USSPACECOM), among others.
By January 2026 the Trump administration renewed its attention on Greenland, arguing that Greenland’s position was crucial for U.S. national security. Indeed, President Trump said in a press conference aboard Air Force One that it “is so much better for us and for Europe to have that piece of ice covered by the Golden Dome,” referring to a missile defense shield concept that would “deter and defend its citizens and critical infrastructure against any foreign aerial attack on the Homeland.”
Greenland’s renewed attention thus offers a chance to examine its place in unified military planning as a major node that [sometimes confusingly] intersects NORAD & USNORTHCOM, USSTRATCOM, and USSPACECOM missions. U.S. military infrastructure in Greenland does not contain missile interceptors, yet Pituffik Space Base (formerly known as Thule Air Base) is home to an Upgraded Early Warning Radar (UEWR) that plays a vital role in early warning of a possible missile launch. This paper begins by clarifying the distinct, yet overlapping concepts of NC3 and missile defense, and then contextualize a core component of recent geopolitical interest in Greenland by examining how existing military infrastructure has supported these concepts from the Cold War through the present era.
NC3 and Missile Defense Architecture
Underpinning the U.S.’ deterrence strategy is the concept that communications must be assured from times of peace through times of conflict. In a nuclear context, communications continuously relay data and transmit messages between sensors, military forces and assets, national leaders, and the President of the United States. This concept embodies nuclear command, control, and communications (or nuclear C3 or NC3), a core responsibility of USSTRATCOM. The multi-domain systems that enable NC3 architecture consist of “…early warning satellites, radars, and sensors; facilities to collect and interpret early-warning information; fixed and mobile networked command posts; and a communications infrastructure that includes land lines, satellite links, radars, radios, and receiving terminals in ground stations and aboard strike vehicles; and the shooters themselves, the nuclear triad of delivery vehicles.” Essentially, NC3’s massive constellation of disparate, yet redundant and resilient systems enables the command and control of nuclear operations (NC2).
NC3’s five functions consist of Situation Monitoring, Planning, Decision-Making, Force Management, and Force Direction. Situation Monitoring, for which Greenland has played an instrumental role, includes a vast array of multi-domain systems “…relating to the collection, maintenance, assessment, and dissemination of information on friendly forces; adversary forces and possible targets; emerging nuclear powers; and military, political, environmental, and other events.” Adding an additional layer of complexity is the role of Integrated Tactical Warning and Attack Assessment (ITW/AA)—a multi-domain system in its own right and a responsibility of NORAD—that fundamentally contributes to the Situation Monitoring mission by providing early characterization of possible missile launches.
Whereas NC3 enables authorized employment and termination of nuclear operations, missile defense focuses on interception of conventional and nuclear weapons. It is succinctly described as “A bullet hitting a bullet… An enemy would launch an intercontinental ballistic missile (ICBM) at the United States; we would detect and track it; then we would launch an interceptor that would ram into the oncoming missile and destroy it entirely.”
NC3 and missile defense architectures are challenging to comprehend. They perform distinct missions, yet share certain overlapping infrastructure; they relay data to decision-makers, yet that information may be stove-piped. To make matters more complex, assets may be shared between multiple Combatant Commands (e.g. USSTRATCOM and NC3, NORAD and ITW/AA, USSPACECOM and sensors, and asset location and homeland defense in and for USNORTHCOM), and data relayed to various command centers for overlapping and/or divergent purposes.
North American missile defense uses a sophisticated, multi-layered and multi-domain system designed to detect, track, and intercept ballistic threats during launch, mid-course, and terminal phases of flight. There are four components to the Ballistic Missile Defense System (BMDS): the Ground-based Midcourse Defense (GMD), Aegis Ballistic Missile Defense, PATRIOT Advanced Capability-3, and Terminal High Altitude Aera Defense (THAAD). Missile defense, much like NC3 and ITW/AA, begins with a detection phase. Today, multiple [potentially overlapping] assets provide indications and warning of a possible launch. For example, the Space-Based Infrared System (SBIRS) uses multiple sensors to identify the infrared heat patterns of missile plumes. SBIRS relies on ground stations, satellites in geosynchronous orbit (GEO) that provide continuous visibility over a wide swath of the Earth, as well as systems in highly elliptical orbit (HEO) that provide extended coverage over the North Pole. Terrestrial warning systems independently and simultaneously (depending on where the missiles are launched) provide additional identification and characterization, known as dual phenomenology. Given the Arctic’s strategic location as the primary route for bomber and missile overflight during the Cold War, these terrestrial and space-based early warning systems help to reduce Arctic blind spots and provide initial trajectory information. These encompass the five Upgraded Early Warning Radars (UEWR), including those in Clear, Alaska and Pituffik, Greenland, capable of surveilling objects over 3,000 miles away; the sixty-odd Alaska Radar System (ARS) and North Warning System (NWS) long- and short-range radar sites that detect strategic bombers and cruise missiles; and Over-the-Horizon (OTH) Radars, which use ionospheric reflection to detect distant threats.[1]
Once a threat is identified, high-fidelity sensors improve the tracking data, yet where that data is relayed can be confusing. Depending on the system, ITW/AA information may be routed through USSPACECOM’s Missile Warning Center, whereas missile defense-supporting sensors may relay information through BMDS’ Command and Control, Battle Management, and Communications System (C2BMC), etc. Concurrently, this information is also supplemented by the Long-Range Discrimination Radar (LRDR) at Clear Space Force Station and the floating Sea-based X-band Radar (SBX) in the Pacific Ocean, which provide high-definition tracking that can distinguish real warheads from decoys. Specialized assets like the COBRA DANE radar on Shemya Island add to this picket line, providing deep-look surveillance of northern approaches that might otherwise be obscured by atmospheric interference or orbital limitations.
Once a missile has launched, personnel at NORAD and USNORTHCOM validate this information to make attack assessments and to inform missile defense and nuclear deterrence decision-making. This phase illustrates the Sensor-to-Shooter loop, or Kill Chain, facilitating efficient data transfer. Secure networks and tactical data links, such as Link 16, transmit targeting information to the In-Flight Interceptor Communications System (IFICS), which delivers real-time course corrections to interceptors. Present initiatives like JADC2 are transforming this process into a mesh network, allowing any sensor, whether a radar in the Aleutians or a satellite over the Pole, to provide data to any available interceptor. This also speaks to the Combatant Commanders’ dilemmas, where there are only minutes to weigh escalation risks and an indication that neither missile defense nor strategic deterrence are not mechanical processes alone.
The Engagement phase is organized into three stages of a missile’s flight, with the Midcourse phase as the primary focus for homeland defense. Ground-Based Interceptors (GBIs), launched from sites such as Fort Greely, Alaska, and Vandenberg Space Force Base, California, exit the atmosphere to engage the target in space. Using hit-to-kill technology, an Exoatmospheric Kill Vehicle (EKV) separates from the booster and uses its own sensors to steer into the warhead. Should a threat bypass this layer, terminal systems like THAAD or Patriot serve as a final catch-all as the missile re-enters the atmosphere. Additionally, unlike GBI’s, THAAD must intercept targets plunging at Mach 10 within thirty seconds.
After engagement, the process concludes with a Kill Assessment. Specialized sensors, such as the Sea-Based X-band Radar (SBX-1), monitor the impact zone to confirm target destruction. If the assessment is inconclusive, the system may employ a shoot-look-shoot approach, launching additional interceptors if time allows. This entire sequence, from initial detection using space- and terrestrial-warning assets to final confirmation, unfolds within minutes and demands accurate coordination across the space, land, and sea domains. Understanding this modern architecture is essential for evaluating how Greenland’s role has shifted from the Cold War’s detect-and-warn paradigm to today’s requirements for continuous tracking and rapid engagement.
The Role of Greenland – Cold War Versus Contemporary Circumstances
Pituffik During the Cold War
Greenland’s relatively limited missile defense architecture, compared with the continental United States and Canada, is not the result of neglect or a lack of strategic importance. Instead, it reflects deliberate choices shaped by mission design, geography, Cold War legacy decisions, and alliance politics – choices that gave Greenland a highly specific and critical role within North American defense.
In the early days of the Cold War, American planners commissioned the installation of a series of radar systems across Alaska, Canada, and Greenland. The Pinetree Line and Distant Early Warning (DEW) Line were built to warn against Soviet bombers flying across the Arctic into North American airspace. While these radars provided a few hours of warning time, advances in missile technology outpaced the installation of these radars. As the Cold War progressed, Thule Air Base was designed as a forward early warning site focused on detecting Soviet intercontinental ballistic missiles (ICBMs) and, increasingly, submarine-launched ballistic missiles (SLBMs) traveling over the Arctic. The shortest and fastest routes for both land-based and sea-based nuclear missiles from the Soviet Union to North America ran across the circumpolar region. Large, fixed radars at Thule helped provide early detection of high-altitude ballistic trajectories, buying critical minutes for U.S. and Canadian leaders to assess whether an attack was underway and how to respond, exemplifying early days of NC3, strategic operations, and the forerunner to missile defense. Yet the mission was intentionally limited: detect and warn, not intercept. This fit Cold War deterrence logic, which sought order by avoiding forward-based missile defenses that could be seen as threatening an adversary’s nuclear second-strike forces, especially those carried by submarines.
While space-based sensors are critical, satellites present limitations for missile defense involving high latitudes (above 65 degrees north). They are costly, limited in number, susceptible to disruption, and constrained by orbital mechanics. No single satellite can maintain continuous surveillance of a target, and effective tracking requires complex handoffs as satellites move in and out of view, with at least four satellites needed for trilateration and accurate flight path calculation. These transitions can introduce gaps, latency, and track ambiguity, particularly against fast, maneuvering threats. During the Cold War, this issue was less pronounced because missile defense relied primarily on ground-based radars detecting high-altitude ballistic missiles on predictable trajectories. This approach was effective since ICBMs and SLBMs traveled mostly above the atmosphere. However, hypersonic weapons challenge this model by flying at lower altitudes, maneuvering laterally, and exploiting sensor gaps. Consequently, modern defense requires layered, overlapping sensors that integrate space and ground assets to ensure continuous tracking, especially across the Arctic and other northern approaches.
Contemporary Challenges and Continuity
Following the Cold War, Pituffik’s primary mission remained consistent in spite of technological improvements and modernization efforts. The UEWR continued to support NORAD and USSTRATCOM and, subsequently, USSPACECOM (and USNORTHCOM when Greenland was aligned in its area of responsibility) by detecting ICBM and SLBM launches, particularly from Russian territory or ballistic missile submarines in northern waters. Although the United States deployed missile interceptors in Alaska and California, Greenland remained a sensor-only site. This was a deliberate strategic decision: early warning and tracking would occur forward, while interception would take place deeper within U.S. territory. Political considerations were also significant; Greenland’s status within the Kingdom of Denmark and its increasing self-governance rendered extensive missile defense basing both politically sensitive and unnecessary for Pituffik’s intended mission.
The strategic environment has evolved. Although ICBMs and SLBMs continue to underpin nuclear deterrence, they are no longer the sole focus of homeland defense. Russia and China now deploy advanced hypersonic glide vehicles, hypersonic and advanced cruise missiles, and other systems able to launch from aircraft, ships, submarines, or mobile land platforms. Unlike traditional ballistic missiles, these weapons often fly at lower altitudes, maneuver during flight, and approach from unpredictable directions. This complexity complicates detection and tracking, in contrast to the predictable trajectories of ICBMs and SLBMs. Consequently, effective defense now requires continuous tracking and rapid integration of sensor data, instead of relying solely on launch detection. To make matters worse, the entire system must be prepared to manage different types of missiles simultaneously, a daunting challenge for any missile defense system.
In response, Pituffik’s function as a ballistic missile warning site has expanded to become a fully integrated sensor node within a comprehensive homeland defense network. While the base continues to detect ICBM and SLBM launches across the Arctic, its value now extends to retaining track custody on a wider array of threats. Radar data from Pituffik is integrated with space-based sensors, Arctic over-the-horizon radar, and other North American systems, adding to a unified picture of missile and air threats. Practically, Pituffik enables earlier detection, extended tracking, and reduced uncertainty, regardless of whether the threat originates from a land-based missile field, a ballistic missile submarine, or a high-speed air-breathing weapon.
Under the proposed Golden Dome homeland defense concept, Pituffik is not intended to serve as a missile interceptor base. Instead, it operates as a critical node supporting the entire defensive chain. The Golden Dome architecture utilizes multiple layers: space-based sensors detect and track ICBMs, SLBMs, and hypersonic weapons globally, forward nodes, such as Pituffik, refine and confirm tracks over the Arctic, command systems determine appropriate responses, and defensive forces, often located far from Greenland, execute engagements. In this system, Pituffik’s primary value lies in supporting timely, informed engagement elsewhere, ensuring decision-makers and defenders have the time and confidence to act within the sensor-to-shooter loop.
As Pituffik assumes a more central role in tracking both ballistic missiles, including SLBMs, and advanced maneuvering threats, protecting the base itself becomes a critical homeland defense issue. A successful attack on this key sensor node could compromise the entire defense system, or at the very least partially blind the missile defense network. Consequently, there is increased emphasis upon resilience measures, such as hardened infrastructure, redundant communications, reliable power supplies, rapid repair capabilities, and limited point defenses against cruise missiles or drones – mainly through short- and medium-range air defense to support Integrated Air and Missile Defense (IAMD). These plans concentrate on protecting the defense network rather than converting Greenland into a forward missile shield.
Any modification to Pituffik’s role must consider alliance politics and issues of sovereignty. Greenland’s status within the Kingdom of Denmark, its increasing self-governance, and NATO sensitivities all support an incremental approach. This entails expanding sensing capabilities, improving integration, and improving resilience, while refraining from the permanent forward deployment of strategic interceptors, which could be perceived as destabilizing, especially regarding adversary SLBM forces.
During the Cold War, Pituffik was established to detect ICBMs and SLBMs traversing the Arctic, to provide early warning of nuclear attack to North America, and to support NC3. While this mission remains vital, the base is now evolving into a critical northern node that supports detection, tracking, and decision-making for a wider range of missile threats. Within a Golden Dome–style architecture, Pituffik’s role supports the entire homeland defense chain in addition to NC3, yet it does not serve as a front-line missile defense base. Table 1 summarizes these contrasts across numerous dimensions, including threat profiles, sensor architectures, tracking requirements, and Greenland’s evolving strategic value. These dimensions reflect the transition from a detect-and-warn posture during the Cold War to the integrated, continuous-tracking model required to counter today’s hypersonic and maneuvering threats.
Table 1: Strategic Deterrence, Missile Defense, and Greenland: Cold War vs. Today
Conclusion
As Table 1 illustrates, contemporary North American defense is no longer governed by the binary detect-and-warn paradigm of the Cold War. Indeed, the proliferation of Combatant Commands in the post-Cold War era reveals that unified military planning in the twenty-first century is no easy task: a singular asset in Greenland supporting NORAD, USSTRATCOM, and USSPACECOM missions in NORTHCOM’s area of responsibility inevitably illustrates the seams that arise in unified military planning for strategic nuclear operations and missile defense. Then-USSTRATCOM Commander General Anthony J. Cotton highlighted the intricacies of disparate, yet overlapping security architecture in 2025:
Maintaining USSTRATCOM’s ability to deter and respond to strategic attack… requires defenses against all types of advanced missiles and other novel delivery systems… Pursuant to [Golden Dome for America] and in cooperation with the Office of the Secretary of Defense, U.S. Northern Command, and other DoD stakeholders, we are actively assessing strategic missile threats and prioritizing a set of locations to defend against a counter-value attack… Defending North America—to include the Arctic—is inherently linked to the ability of the Joint Force to operate. We also support improvements in early warning, identification, tracking, discrimination, and attribution for the full range of advanced air and missile threats to the homeland and our strategic forces to support U.S. Space Command’s trans-regional missile defense responsibilities.
Modern threats necessitate countering legacy weapons as well as the flight altitude and maneuverability of rapidly advancing hypersonic threats. Unlike traditional ballistic missiles, which follow predictable trajectories, hypersonic weapons exploit sensor gaps by flying at lower altitudes and maneuvering, rendering reliance on upward-looking sensors inadequate as well as interceptors. Meeting this challenge requires the seamless integration of Pituffik Space Base as a critical node within the Golden Dome system. Transforming Pituffik from a standalone warning site into a high-fidelity sensor node enables the network to bridge gaps between space-based tracking and terrestrial interception, ensuring continuous track custody, which is essential for a modern Sensor-to-Shooter loop. As the table indicates, system vulnerability concerns have shifted from limited to high, meaning that strategic priorities must include enhancing the base’s resilience against emerging threats such as drones and cruise missiles, which will help to preserve the integrity of the North American defense network. Ultimately, while Greenland’s strategic value during the Cold War bolstered early warning and strategic deterrence, it now encompasses early warning, persistent tracking, and decision-time extension, making Pituffik indispensable to the layered, networked, multi-domain architecture that defines 21st-century strategic nuclear operations, NC3, and homeland defense.
Disclaimer: The views in this chapter are solely those of the authors and do not necessarily represent the official views, policies, or positions of the U.S. Department of War, the U.S. government, or the authors’ assigned institutions.
[1] UEWRs are located in Alaska, California, Massachusetts, Greenland, and Great Britain.
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