When US President Donald Trump talks about acquiring Greenland, it is tempting to dismiss the idea as another provocation — half joke, half boast, quickly forgotten.
That would be a mistake. The proposal makes no legal, political or strategic sense. But it is revealing. Not because it could ever happen, but because it exposes a deeper shift in how power, sovereignty and global order are now being framed.
Trump first floated the idea of “buying” Greenland in 2019, and he has since revived it recently, together with a 20-day deadline.
Each time, the response has been swift and categorical: Greenland is not for sale; Denmark is not selling; the matter is closed. And yet the idea keeps resurfacing. Why?
Assets of empires no longer exist
To understand why the Greenland proposal is fundamentally unworkable, one must start with history.
Yes, the United States has bought land before. Alaska was purchased from Russia in 1867. The Danish West Indies — today’s US Virgin Islands — were bought from Denmark in 1917 for $25 million in gold.
These precedents are often invoked by Trump and his MAGA supporters as proof that territorial acquisition by purchase is normal, even sensible.
But these transactions took place in a very different world: a colonial, pre-1945 international order, before the United Nations Charter, before modern norms of sovereignty, and before the right of peoples to self-determination became a cornerstone of international law.
In those cases, territories were treated as assets of empires. Their populations had little or no say. That legal and moral framework no longer exists.
Greenland today is not a colonial outpost waiting to be transferred. It is a self-governing territory with its own parliament, government and political debate.
Crucially, Greenlanders have a recognised right to independence should they choose it. Any attempt to “sell” Greenland would violate not only international law, but the democratic agency of its people.
Sovereignty is not a commodity; it cannot be priced, packaged or traded.
Leap from strategic importance to territorial acquisition
The idea also collapses on political grounds. Denmark is a stable democracy, a NATO ally and a close partner of the United States.
The notion that Washington could purchase territory from Copenhagen belongs to a nineteenth-century playbook, not to alliance politics in the twenty-first century.
Such a move would be politically explosive in Denmark, unacceptable in Greenland, and deeply destabilising within NATO itself.
Then there is the strategic argument, often presented as the strongest justification. Greenland matters, it is said, because of the Arctic, great-power competition, rare earths, shipping routes and missile defence.
All of this is true. What is false is the leap from strategic importance to territorial acquisition.
The United States already enjoys extensive strategic access to Greenland. It operates military facilities there, benefits from intelligence infrastructure, and works closely with Denmark on Arctic security.
Ownership would add little operational value while dramatically increasing political cost. From a strategic standpoint, buying Greenland would be redundant; from an alliance-management perspective, it would be self-sabotage.
Why, then, does the idea persist? Because it fits a particular worldview: one that sees international relations as a series of deals, leverage points and zero-sum transactions.
In this “Trumpian” conception of geopolitics, power is demonstrated through ownership, control and spectacle. The language of real estate replaces the language of diplomacy. Influence is confused with possession.
This is not just a personal idiosyncrasy. It reflects a broader erosion of the post-war international order, in which rules, institutions and shared norms are increasingly challenged by raw power politics.
In that sense, Greenland is less a policy proposal than a symbol: a way of signalling dominance, impatience with constraints, and nostalgia for a world where might made right.
Rules are being tested, but should not be bent
For Europe and the UK, this matters. Not because Greenland might change hands, but because it illustrates the kind of geopolitical environment we are now operating in.
An environment where allies may be spoken of transactionally, where sovereignty is rhetorically downgraded, and where strategic discourse borrows the language of acquisition rather than cooperation.
The real question, therefore, is not whether the United States can buy Greenland. It cannot. The real question is how Western democracies respond to a geopolitical climate in which such ideas are voiced at all.
The challenge is to defend sovereignty without sliding into paralysis; to manage competition without abandoning law; and to maintain alliances in a world where transactional instincts are once again ascendant.
Greenland is not for sale. But the episode is a reminder that the rules of the game are being tested. And that complacency about those rules would be the costliest mistake of all.
Aurélien Colson is professor of political science and co-academic director of the Institute for Geopolitics & Business at ESSEC Business School.