Though these efforts both failed, they might suggest that selling Greenland is within the realm of possibility. But many things have changed since the 1940s—among them global recognition of the principle that peoples and nations have a right to self-determination under international law. Expressly recognized in Article 1(2) of the U.N. Charter and further developed through a series of resolutions, this principle is now recognized by the International Court of Justice as an accepted part of customary international law. While the precise contours of this obligation and how it should be implemented are unclear and often disputed, the principle drove the decolonization process that began in earnest in the 1960s and has played a prominent role in efforts to give the residents of various territories a substantial say in those territories’ sovereign status and governance. In this sense, self-determination has complicated a number of practices that were once historically commonplace—including the exchange of populated territories between states.

In the case of Greenland, the rise of self-determination has manifested as a series of measures giving Greenland increased autonomy. Beginning with the 1978 Home Rule Act, the Kingdom of Denmark has gradually allowed Greenland to exercise self-government over a greater sphere of its affairs, often in response to demands by native Greenland residents. Most recently, in 2009, this trend resulted in the Act on Greenland Self-Government, which expressly recognized that “the people of Greenland is a people pursuant to international law with the right of self-determination” and devolved control over an even greater scope of activities to Greenland’s own government. This includes foreign affairs: The legislation authorized Greenland to enter into international agreements on its own regarding matters that solely affect Greenland’s interests, while setting up consultation requirements for any international agreements that Denmark may wish to pursue that implicate Greenland. Finally, the act also sets out a process through which Greenland can choose to seek its own independence. This process ultimately requires a referendum of Greenland residents as well as approval by the parliaments of both Denmark and Greenland.