EU Defense Capabilities Against US Attack on Greenland: A Fact Check

In a geopolitical scenario that once seemed implausible, European nations could find themselves legally obligated to defend Greenland against U.S. aggression under existing defense agreements. This complex situation highlights the interconnected nature of international defense commitments and raises questions about potential conflicts of interest among Western allies.

Greenland, an autonomous territory within the Kingdom of Denmark, enjoys protection under multiple defense frameworks that bind European nations to its defense. The North Atlantic Treaty Organization’s Article 5 collective defense provision and the European Union’s mutual defense clause both create obligations that could theoretically be triggered if Greenland faced military aggression—even from a NATO founding member like the United States.

NATO’s Article 5, the cornerstone of the alliance since 1949, states that an attack against one member shall be considered an attack against all members, compelling collective action in response. As Denmark is a NATO member, this protection extends to Greenland as Danish territory.

Similarly, the European Union’s mutual defense clause, Article 42.7 of the Treaty on European Union, obligates EU member states to provide “aid and assistance by all means in their power” if another member state suffers armed aggression on its territory. This would also include Denmark and, by extension, Greenland.

“These overlapping defense commitments create an unusual legal predicament,” explains Dr. Elena Korhonen, international security expert at the University of Copenhagen. “European nations would theoretically be bound by two separate treaty obligations to defend Greenland against any aggressor, including the United States—despite the U.S. itself being a NATO ally.”

The scenario, while currently hypothetical, underscores growing tensions over Arctic resources and territorial claims as climate change makes the region more accessible. Greenland possesses vast mineral deposits and strategic importance, with melting ice revealing potential new shipping routes and natural resources.

The U.S. has previously shown direct interest in Greenland, most notably in 2019 when former President Donald Trump suggested purchasing the territory—a proposal quickly rejected by both Greenland and Denmark. However, the strategic importance of Greenland has only grown in recent years as Russia and China have increased their Arctic presence.

“What makes this situation particularly complex is that the United States itself has a military presence in Greenland through Thule Air Base,” notes Dr. Marcus Johannsen, defense analyst at the European Council on Foreign Relations. “This creates a web of relationships where the very nation hypothetically posing a threat also maintains crucial defense infrastructure on the territory.”

Legal experts point out that while the defense clauses are clear in principle, their application in such an unprecedented scenario would likely trigger a severe diplomatic crisis and test the foundations of transatlantic relations.

The situation also raises questions about prioritization of commitments for countries with dual NATO and EU membership. Most European nations belong to both organizations, potentially creating competing obligations in the unlikely but theoretically possible scenario of U.S. aggression toward Greenland.

Defense ministers across Europe have been reluctant to comment publicly on this hypothetical scenario, understandably wishing to avoid creating diplomatic tensions over what remains a speculative situation. NATO officials similarly decline to discuss potential conflicts between member states, emphasizing instead the alliance’s role in maintaining collective security.

Climate researchers note that as Arctic ice continues to recede at record rates, competition for newly accessible resources may intensify, potentially creating more friction points between allies with interests in the region.

For Greenland’s 56,000 residents, these geopolitical chess moves represent more than theoretical discussions. The territory has been moving toward greater autonomy from Denmark, with some political movements advocating for eventual independence—a development that would further complicate the existing defense arrangements.

As global warming transforms the Arctic landscape and geopolitical tensions evolve, the question of who would defend Greenland—and against whom—remains a reminder of how traditional alliances may face unprecedented tests in the changing global security environment.