Trump says Greenland is vital to US national security because of its strategic position in the Arctic, particularly in the context of growing competition with China and Russia. He argues only direct US control can guarantee long-term security.

However, the US already has extensive military access under a longstanding 1951 defence agreement on Greenland with Denmark. Under this framework, the USA operates the Pituffik Space Base and has never been prevented from carrying out military activities it has requested. Greenland is also covered by NATO’s collective defence agreement, since Denmark is a NATO member.

This system has benefited the USA directly in the past. NATO’s article 5 commits all members to treat an attack on one as an attack on all. The USA is the only country to have formally invoked this article in the alliance’s history: after the 9/11 attacks, NATO allies, including Denmark, came to the USA’s defence. Denmark sent troops to Afghanistan and lost many soldiers there.

Given this level of existing military access and support, it’s difficult to see how US security needs in Greenland are not already being met.

It’s hard to predict what tangible steps the USA might take. Trump has not ruled out any option, including the use of force, but a military intervention would come at an enormous cost. Denmark’s prime minister, Mette Frederiksen, and other European leaders have warned that a US attack on Greenland would effectively end NATO, potentially leading allies to close US bases, scale back intelligence cooperation and reduce purchases of US military equipment.

There are also practical limits. The capital, Nuuk, has fewer than 20,000 inhabitants, but Greenland covers over two million square kilometres. Even if the USA could control Nuuk, occupying the territory from coast to coast would be impossible.

For this reason, most Americans who support this idea – and they appear to be a small minority – argue instead for persuading Greenlanders to align with the USA, for example by exercising their right to self-determination to leave the Kingdom of Denmark and join the USA.

Greenlanders have been very clear that they don’t want to move from being the colony of one country to becoming the colony of another. As Sara Olsvig, Chair of Inuit Circumpolar Council, an organisation representing Inuit interests globally, put it: ‘there is no such thing as the better coloniser.’

In Greenland, while it is more than negligible, there is very little public support for joining the USA. While there are different views on how quickly Greenland should change its relationship with Denmark, there is broad agreement on one point: decisions about Greenland’s future must be made by Greenlanders themselves, without external pressure and on their own terms.

Trump has said he’s not constrained by international law, only by his own ‘morality’. Although he later partly retreated from this position and claimed his actions are compatible with international law, the conduct of his administration suggests otherwise. Whether through trade measures and tariffs, the use of force against fishing vessels accused of trafficking, or the abduction of a sitting president, actions suggest his administration is simply not concerned with legal boundaries.

The broader risk is that weakening respect for international law encourages other states to act in the same way. If those norms are eroded, small states and territories are the first to be exposed. They depend on alliances, legal rules and multilateral institutions for protection and trade. Without them, they are left with little defence in a world where power, not rules, decides their fate.