The primary treaty governing the U.S. deployment of troops and equipment in Greenland is the 1951 Defense of Greenland Agreement between the United States and the Kingdom of Denmark.
avalon.law.yale.edu
This bilateral agreement, signed on April 27, 1951, was entered into pursuant to the North Atlantic Treaty (NATO) and remains in effect for its duration.
avalon.law.yale.edu
It was amended and supplemented in 2004 to account for Greenland's Home Rule status (established in 1979), recognize the reduction in U.S. defense areas, and incorporate additional provisions on consultation, local cooperation, and environmental protections.
state.gov
The agreement allows the U.S. broad rights to establish and operate military facilities in Greenland for the defense of Greenland and the broader North Atlantic Treaty area, including stationing personnel, storing supplies and equipment, constructing installations, and conducting operations such as aircraft flights and ship movements.
avalon.law.yale.edu
While the agreement is permissive and grants the U.S. significant flexibility to expand its presence as needed for NATO-approved defense purposes (with analysts noting it allows increases "almost at will"),
nytimes.com
it imposes several procedural, operational, and purpose-based limitations:
- Purpose and Scope Restrictions: All U.S. activities must be tied to NATO defense objectives for Greenland and the North Atlantic area. They are confined to designated "defense areas," with Thule Air Base (now Pituffik Space Base) as the only current such area; establishing new ones requires Denmark to grant necessary rights under mutually agreed conditions, in line with NATO plans.
avalon.law.yale.edu +1
- Consultation and Cooperation Requirements: The U.S. must consult with Danish authorities (including Greenland's Home Rule Government) on matters affecting Danish or Greenlandic interests, such as significant changes to operations or facilities, exceptional military aircraft landings outside airports (to protect the environment and hunting areas), and local affairs. A Greenlandic representative may be appointed to consult with the U.S. commanding officer at Thule. Unresolved issues are escalated through a Permanent Committee or diplomatic channels.
avalon.law.yale.edu +1
- Environmental Protections: U.S. forces must respect Greenland Home Rule environmental standards, with the more protective of U.S. or Greenlandic rules applying via updated Final Governing Standards. An Environmental Subcommittee addresses contamination risks, pollution prevention, and nature protection, with regular meetings and information exchange. Danish and Greenlandic authorities have access to Thule for environmental assessments, subject to security and safety constraints.
state.gov
- Shared Use and Sovereignty: Denmark reserves the right to cooperatively use defense areas without impeding U.S. operations. The flags of Denmark, Greenland, and the U.S. must fly over Thule. U.S. activities must respect Danish laws, regulations, and customs, including cooperation on entry/exit of personnel and avoiding interference with Danish responsibilities outside defense areas (e.g., shipping and aviation rules).
avalon.law.yale.edu +1
- Jurisdictional and Administrative Limits: Jurisdiction over U.S. personnel in defense areas generally falls to the U.S., but is supplemented by the NATO Status of Forces Agreement (SOFA). There are no visa restrictions for U.S. military/civilian personnel and dependents, but movements and access are subject to mutual agreements. Danish assistance is required for base security as appropriate.
avalon.law.yale.edu +1
The agreement does not impose numerical caps on troops, equipment, or deployments, nor does it explicitly prohibit nuclear weapons (though historical deployments were handled secretly under Denmark's broader no-nuclear policy, and none are present today).
nsarchive.gwu.edu
Modifications can be proposed by either party based on experience or NATO needs, requiring mutual consent.
avalon.law.yale.edu