Greenland has moved from the margins of global affairs to the centre of strategic debate after renewed and unusually blunt remarks by President Donald Trump, who has argued that United States (US) control over the world’s largest island is essential for American national security.

Formally, Greenland remains part of the Kingdom of Denmark, with extensive self-government and an explicit right to independence under its 2009 Self-Government Act. In practice, however, Greenland’s security is inseparable from wider North Atlantic defence.

The island sits astride the GIUK Gap, the critical maritime corridor linking Greenland, Iceland, and the United Kingdom, and occupies the shortest routes for missile and submarine traffic between Eurasia and North America. Control of that space is central to early warning, missile defence, and protection of the US eastern seaboard.

This is where European assurances begin to look thin. European governments insist they can keep Greenland out of Chinese or Russian hands, yet Europe has struggled to secure its own eastern flank without extensive US funding, intelligence, logistics, and force projection. The defence of Ukraine, the Baltics, and the North Atlantic Treaty Organisation’s eastern perimeter has depended decisively on American military power. Europe’s defence spending, readiness, and industrial capacity have not been sufficient to deter Russia independently, even on a single front.

Greenland exposes the implication of that imbalance. If Europe cannot credibly secure its eastern frontier without US backing, it is hard to argue that it can simultaneously police and defend its western and northern approaches in the Arctic. The notion that Europe could sustain deterrence against Russia in Eastern Europe while also countering Chinese or Russian influence in Greenland assumes a level of strategic depth and military capacity that Europe does not currently possess. Fighting, or even deterring, on two fronts is beyond its demonstrated capability.

Then there is the question, seldom aired in the media, that Greenlanders may in practice choose autonomy by a simple referendum, that Denmark and Europe are on the record that they would accept that result, and that such a referendum may not favour the West.

For Washington, this is not an abstract concern. The United States already maintains a military presence on Greenland through the Pituffik Space Base, a cornerstone of missile warning and space surveillance since the Cold War. American planners see Greenland not as a European peripheral, but as a keystone of North Atlantic defence. If effective Western control over the island were to weaken, the vulnerability would not stop at Europe’s borders. It would extend directly to the US homeland.

China’s earlier attempts to invest in Greenlandic infrastructure and mining projects, alongside its declared ambition to become a “polar great power”, sharpened these anxieties. While Beijing’s footprint has so far been constrained by US pressure, Chinese Arctic policy has reinforced Washington’s view that Greenland cannot be treated as strategically inert. Russia’s expanding Arctic capabilities add a parallel pressure from the opposite direction.

What Trump’s intervention ultimately reflects is a loss of confidence (not without merit) in Europe’s ability to manage this risk alone. From a US perspective, relying on European guarantees that are themselves underwritten by American power amounts to circular logic. If the US is already the backstop for Europe’s security, then ambiguity over who truly guarantees Greenland’s defence becomes a strategic liability.

What happens next is unlikely to resemble the crude scenarios implied by Trump’s critics. A war between the US and Europe or equally crude military takeover is implausible. But outright purchase remains plausible. The more probable outcome into the medium term, however, is intensified US pressure for deeper security integration, expanded basing rights, and tighter control over infrastructure and resource development, ensuring that Greenland remains firmly anchored within the Western security architecture. That may later lead to the more formal “adoption” or “purchase” of Greenland by the US (the US took control via a purchase of the Virgin Islands in the Caribbean from Denmark in 1917).

The issue at its heart is not about sovereignty but about credibility. Europe may retain legal authority over Greenland, but without independent hard power to enforce that authority, its reassurances carry limited weight. In that context, US concerns about Greenland are less a challenge to European ownership than a response to a strategic vacuum. The Arctic is becoming a front line, and at present, Europe is not equipped to hold it without Washington.