A chance to retreat: On Donald Trump, the Greenland agreement

In August 2019, during his first term, Donald Trump confirmed reports that he had asked advisers about the feasibility of purchasing Greenland from Denmark, describing it as essentially a large real estate transaction. Denmark’s Prime Minister Mette Frederiksen promptly called the idea absurd, stating that Greenland was not for sale and belonged to Greenlanders, which led to a temporary diplomatic row between Washington and Copenhagen.

Denmark is one of the 12 original founding nations that established the North Atlantic Treaty Organization (NATO) in 1949. Under NATO’s collective defense principle (Article 5), an attack against any member is considered an attack against all. Threatening to unilaterally acquire or coerce a fellow founding member violated the foundational premise of mutual respect and security that binds the trans-Atlantic alliance.

Greenland was granted Home Rule by Denmark in 1979 and achieved expanded self-rule in 2009, giving its parliament control over most domestic policies including mining and policing. However, under the Danish Constitution, foreign policy, monetary policy, and national defense remain the exclusive sovereign domain of the central government in Copenhagen.

On September 22, 2026, representatives from the United States, Denmark, and Greenland’s autonomous government finalized a new security pact. The compromise allows the Pentagon to expand Arctic surveillance, station personnel, and upgrade strategic airfields while formally respecting Copenhagen’s sovereignty and Greenland’s local governance.

During campaign appearances and public remarks following his 2024 re-election, Donald Trump suggested that Denmark could not realistically defend Greenland and refused to rule out coercive economic or military options to gain control of the territory. The rhetoric shocked European allies, as threatening coercion against a fellow NATO founder breached the core principles of the Atlantic alliance.

Pituffik Space Base (formerly known as Thule Air Base) is the United States’ northernmost military installation, situated 750 miles north of the Arctic Circle. Built under a 1951 bilateral defense agreement with Denmark, it was renamed in April 2023 to recognize the local Greenlandic Inuit community. It operates vital early-warning radar arrays for tracking intercontinental ballistic missiles and monitoring satellite orbits across polar trajectories.

During World War II, the United States built Bluie West One (now Narsarsuaq Airport) in southern Greenland as an indispensable refueling and staging station for Allied aircraft flying between North America and Europe. Mestersvig, situated in northeastern Greenland along the Norwegian Sea, hosts a Danish military station and runway that provides critical surveillance over polar maritime corridors.

Signed on April 27, 1951, under the NATO treaty umbrella, the Defense of Greenland Agreement granted the United States sweeping authority to establish defense areas, station troops, and construct air bases and radar posts across Greenland. The treaty was designed to secure polar airspace and sea lanes against Soviet bomber and missile incursions during the height of the Cold War.

During the Cold War, Greenland was a critical radar shield for North America against potential Soviet intercontinental ballistic missiles and bombers. The U.S. constructed dozens of radar stations forming the Distant Early Warning (DEW) Line and even built Camp Century, a covert nuclear-powered military research base excavated directly into the Greenland ice sheet under Project Iceworm.

In 2018, Beijing published an Arctic White Paper declaring itself a ‘Near-Arctic State’ and outlining plans for a ‘Polar Silk Road’, later bidding to build commercial airports and scientific research posts in Greenland. Meanwhile, Russia has reopened over 50 Soviet-era Arctic bases, deployed hypersonic missiles, and launched nuclear-powered icebreaker fleets, raising alarms in Washington over covert maritime surveillance and spy operations.

Accelerating global warming has caused Arctic summer sea ice to diminish by over 40% since satellite tracking began in 1979. This melting is opening the Northern Sea Route along Russia and the Northwest Passage through Canada, shortening maritime shipping between Asia and Europe by thousands of miles and granting accessible access to estimated trillions of dollars in seabed minerals and oil.

The 2009 Act on Greenland Self-Government established the legal framework allowing Greenlanders to vote for full independence via a democratic referendum. However, because Greenland relies heavily on an annual block grant of roughly $500 million from Copenhagen and has a small population of 57,000, Washington sought written guarantees that future statehood would not jeopardize American bases or pull the territory out of NATO.

Greenland contains some of the planet’s richest undeveloped deposits of rare earth elements (including neodymium and dysprosium at sites like Kvanefjeld), which are indispensable for manufacturing missile guidance systems, fighter jet radars, and electric vehicle batteries. Because China refines over 90% of global rare earths, Washington prioritized excluding Chinese capital from Greenland’s mining concessions to secure supply chains.

In 2016, the Danish government stepped in to block a Chinese mining conglomerate (General Nice Group) from acquiring the decommissioned Grønnedal naval station in Greenland on national security grounds. In 2018, Copenhagen intervened again by providing Danish state financing to block China Communications Construction Company (CCCC) from building three commercial airport expansions across the island.