BRUSSELS — The North Atlantic Treaty Organization (NATO) faces unprecedented internal strain as former U.S. President Donald Trump’s persistent assertions regarding Greenland’s acquisition challenge the alliance’s core principles. This geopolitical tension has escalated to the point where Danish leadership explicitly warns that military action against Greenland would fundamentally rupture NATO’s framework.
Greenland, a semi-autonomous territory within the Kingdom of Denmark, has become an unexpected flashpoint in transatlantic relations. Trump’s reaffirmed stance that “we’re going to have Greenland one way or another,” coupled with the White House’s refusal to dismiss military options, has created diplomatic alarm across European capitals. The administration justified its position as preventive measures against Russian and Chinese expansion in the Arctic.
Danish Prime Minister Mette Frederiksen delivered a stark warning: “Should the United States militarily attack another NATO nation, everything ceases—including our NATO membership.” This declaration underscores the grave implications of intra-alliance aggression.
NATO’s historical context reveals why this situation proves particularly volatile. Established in 1949 by twelve nations to counter Soviet threats, the alliance has expanded to thirty-two members following Sweden’s 2024 accession. Its fundamental operating principle remains consensus decision-making, where each member holds veto power. The organization’s credibility rests upon Article 5’s collective defense pledge, invoked only once following the 9/11 attacks.
Legal analysts note that Article 5 would prove ineffective in a U.S.-Denmark conflict due to required unanimity. Instead, Denmark could trigger Article 4 consultations for sovereignty threats, though such talks don’t mandate military response. The alliance lacks established mechanisms for resolving armed conflict between members.
This scenario echoes the 2003 Iraq War division, where NATO members split between supporters and opponents of U.S. action. Current uncertainty surrounds which nations would endorse Trump’s Greenland position, highlighting the alliance’s fragility when confronted with internal power disparities.
The United States remains NATO’s dominant military and financial contributor, making coherent opposition challenging without American leadership. Daily operations continue under former Dutch Prime Minister Mark Rutte’s diplomatic management, who maintains public neutrality while working to preserve U.S. engagement.
Rutte recently emphasized Arctic security consensus while denying NATO crisis over Greenland: “All allies agree on Arctic importance due to increased Russian and Chinese activity risks.” The organization’s military command, always led by a senior U.S. officer based in Mons, Belgium, continues standard operations amid these political tensions.