Denmark and Greenland propose NATO mission to secure Arctic waters

Denmark and Greenland have formally proposed a NATO mission to operate in Greenland and the wider Arctic, presenting a potential collective-security framework as tensions with the United States escalate over control of the island. The proposal was floated after talks in Brussels between Danish Defence Minister Troels Lund Poulsen, Greenlandic Foreign Minister Vivian Motzfeldt and NATO Secretary General Mark Rutte.

“We have proposed this. The NATO Secretary General has also taken note of this, and I believe we can now hopefully establish a framework for how this can be achieved,” Poulsen said after the meeting, adding the proposal is “in line with what we have discussed with the Greenlandic government.” Officials discussed the initiative under the working name Arctic Sentry; Poulsen said he would “like all countries to be part of Arctic Sentry, at least all NATO countries.” Rutte signalled alliance engagement in a public post, writing that they had discussed “how important the Arctic - including Greenland - is to our collective security & how Denmark is stepping up investments in key capabilities. We'll continue to work together as Allies on these important issues.”

The move is both tactical and political. It aims to provide NATO with a visible remit in the High North while reinforcing Denmark’s constitutional responsibility for Greenland’s defence and engaging Greenland’s own authorities. Yet the initiative raises immediate diplomatic and legal questions: whether Washington will support a formal NATO mission on an autonomous territory whose defence and foreign policy are constitutionally the responsibility of Denmark; how any operation would be mandated under NATO law; and how troop contributions, rules of engagement and basing rights would be negotiated among allies.

Uncertainty about U.S. support hangs over the proposal. Some European ministers declined to say whether Washington would back a NATO role. The initiative has arisen against a backdrop of heightened U.S. pressure, with President Donald Trump intensifying efforts to assert influence over Greenland and reportedly urging the U.S. to “control” the island. That pressure has prompted European capitals to accelerate military activity and diplomatic coordination in the region.

Denmark has already stepped up operations: a Danish-led reconnaissance mission recently mapped options for strengthening military presence, and a multinational exercise called Arctic Endurance involved forces from a wide range of European countries, though several participants ended their deployment early. Danish authorities said a large number of combat soldiers were expected to arrive in Kangerlussuaq, joining roughly 200 Danish troops already split between Nuuk and Kangerlussuaq, with Army Chief Peter Boysen among those deploying.

The diplomatic fallout has triggered talk of an economic response in Brussels. European leaders have discussed potential countermeasures and the use of the EU’s Anti-Coercion Instrument; one German finance minister warned Europe would not be “blackmailed” into ceding control of Greenland. Such talk underscores how disputes over a remote Arctic island can ripple into trade and alliance politics.

For now the Arctic NATO proposal remains exploratory. Danish and Greenlandic officials have signalled intent to work with NATO to develop a framework, and Secretary General Rutte has taken note. Key next steps include clarifying the mission’s legal basis, securing allied buy-in, most importantly from the United States, and ensuring the plan respects Greenlandic autonomy and indigenous voices as operational details are hammered out. Rutte is scheduled to meet President Trump in Davos, where further talks on Greenland are expected.