International law principles regarding territorial sovereignty and self-determination create legal frameworks that President Trump’s annexation campaign would violate, providing Greenland and Denmark with legal grounds to resist American pressure while potentially enabling international responses to defend against forcible territorial changes. These legal principles, developed over centuries and codified in modern treaties, represent fundamental rules governing relations between states.
The United Nations Charter prohibits the threat or use of force against the territorial integrity or political independence of any state, establishing a foundational principle of modern international law. Article 2(4) of the Charter creates a legal obligation for all UN member states to refrain from threatening or using force to alter borders or political arrangements. Trump’s threats regarding Greenland potentially violate this fundamental principle if they constitute genuine threats of force rather than mere diplomatic pressure.
The principle of self-determination, recognized in numerous international instruments including the UN Charter and International Covenant on Civil and Political Rights, establishes that peoples have the right to freely determine their political status and pursue economic, social, and cultural development. Greenlanders as a recognized “people” under the 2009 Self-Government Act possess self-determination rights that external powers must respect. American imposition of control without genuine Greenlandic consent would violate these principles.
Customary international law regarding territorial acquisition prohibits conquest and forcible annexation, establishing that territorial changes must result from legitimate processes including treaties, peaceful cession, or genuine expressions of self-determination. The legal maxim “ex injuria jus non oritur” (law does not arise from injustice) means that rights cannot be created through illegal acts. Even if Trump successfully seized Greenland through force, international law would not recognize American sovereignty acquired through illegal means.
Danish Prime Minister Mette Frederiksen warned that any US military action would destroy NATO. Greenland Prime Minister Jens-Frederik Nielsen demanded Trump respect international law. European nations unified in supporting these legal principles. The international legal framework creates obligations on all states to respect territorial integrity and self-determination, potentially enabling collective international responses if Trump violates these fundamental principles. While enforcement mechanisms have limitations, legal principles provide moral authority and potential foundations for coordinated resistance to illegal territorial aggression.