How US Could Annex Greenland

The White House has left open the possibility of annexing Greenland by force - a gamble that could collapse NATO and ignite a geopolitical firestorm.

President Donald Trump and his top officials have framed their drive for Greenland - a semi-autonomous Danish territory - as all about U.S. national security, broader NATO footprints in the increasingly competitive Arctic and grabbing critical minerals.

This is a somewhat thin justification. The U.S. has for many decades had a defense agreement with Copenhagen to keep a military presence in Greenland.

Plus, much of the concern plaguing Europe for the last year is built on a fear of the U.S. pulling away from the continent - not committing more American troops to a region NATO is desperate to safeguard against growing Russian and Chinese influence.

Most important, many say, is the so-called "Donroe Doctrine" - a play on the Monroe Doctrine - signaling the administration's push to reassert U.S. dominance across the Western Hemisphere.

The White House has not clarified what course it may opt to take. Swirling around is talk about buying the strategic Arctic island via some form of deal, often in the same breath as military action. Again, it is not apparent what type of military action the administration could opt for, and this wouldn’t necessarily spell annexation.

But if it did, what would annexation look like?

What Is Annexation?

In simple terms, annexation an act by one state that stakes a territorial claim on areas belonging to another state.

This can be a formal move using legislation, or through “a set of de facto policies on the ground,” said Marko Milanovic, professor of public international law at the University of Reading in England. The idea is to “establish a fait accompli without formally claiming ownership of the territory,” Milanovic told Newsweek.

The International Court of Justice (ICJ), in a 2024 advisory opinion on Israeli actions in areas like the West Bank, defined annexation as “the forcible acquisition by the occupying Power of the territory that it occupies, namely its integration into the

territory of the occupying Power.” Bound up in this action is the intention to “exercise permanent control over the occupied territory,” according to the advisory opinion.

Both formal - de jure -and de facto options for annexation, when enacted without the consent of the state originally controlling the territory, “would be a gross violation of international law,” Milanovic said.

Occupying territory, meanwhile, does not necessarily mean making a claim of sovereignty to the territory or the desire to permanently control it.

What Does International Law Say?

One of the clearest and most cited judgements on annexation is in the United Nations Charter Article 2(4). A cornerstone of international law, it reads: “All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.”

In short, it means changes to which country controls territory should not happen by using the military, or alluding to its possible use.

International law concerns have pursued the administration for months. More than four months of U.S. strikes on alleged drug trafficking vessels in the southern Caribbean and eastern Pacific have raised pressing worries about the legality of American actions abroad from former officials and experts across the globe. More than 100 people have been killed in tens of strikes, according to the administration’s numbers.

What Does the U.S. Constitution Say?

Legally, the U.S. cannot forcefully acquire another territory, said William Banks, professor of law at Syracuse University. “They couldn’t make a move like this without the approval of the Danes,” as well as the Greenlanders, Banks said.

“Our country isn’t something you can deny or take over because you want to,” said Greenland’s prime minister, Jens-Frederik Nielsen, on Monday.

Trump himself could not annex Greenland without Congressional approval - an executive order, for example, would not have any legal authority, Banks told Newsweek. But Congress could vote to approve the annexation of Greenland, overriding international law, Banks said, although it would “be abhorrent to most Americans.” This is because the U.S. Constitution doesn’t set out any boundaries on acquiring territories.

So, if Congress voted for annexation, Denmark could appeal to the ICJ, which is the legal arm of the UN. But even if the ICJ declared the U.S. in violation of international law, there’s little other countries could do about it, because there’s no way to enforce an ICJ ruling.

What Could the U.S. Do With Its Military?

Annexation isn’t the only course of military action. There are already American soldiers in Greenland, stationed at the Pituffik Space Base in the northwest of the island

"They’re already there, with the U.S. flag flying,” said David Blagden, an associate professor of international security and strategy at the University of Exeter in southwest England. Theoretically, they could just pull down the Danish and Greenlandic flags, Blagden told Newsweek.

The big, looming question is how the Danes, and NATO, would respond, and what it would mean for the alliance. Current and former military and diplomatic officials are skeptical Danish soldiers would ever end up fighting American troops, and often shudder to think about it.

“For soldiers who trained and lived together for decades, fought alongside each other in places like Afghanistan and Iraq, its horrific to hear politicians talking about the comrade as an enemy,” a European military source told Newsweek. “It’s against the DNA of NATO soldiers to even think about that.”

But the U.S. is the world’s dominant military power, and the backbone of NATO. Europe and Canada have long relied on America’s military might to prop up the alliance, and observers wince to think of Europe’s prospects against an armed American attack.

A European official, who was granted anonymity to speak freely, told Newsweek there was a sense the U.S. may be emboldened after the operations in Venezuela over the weekend, but they were not actively planning for possible U.S. action against Greenland.

“We trust the Danes have a plan,” the official said.

The White House has said the administration is working on a possible offer to buy Greenland - although Copenhagen and officials in Nuuk have said it’s not for sale. Secretary of State Marco Rubio and Defense Secretary Pete Hegseth are expected to meet with Danish and Greenlandic officials next week.

“You can’t buy anything unless someone is willing to sell it to you,” said Kåre Aas, a former Norwegian ambassador to the U.S. He served in Washington during the first Trump administration.

Safe embed will be rendered here

Greenland vs world rare earth minerals-USGS

Service URL: https://flo.uri.sh/story/3540150/embed

Minerals, Security, Or Control?

Vice President JD Vance, speaking to Fox News in an interview published on Wednesday, said Trump was “willing to go as far as he has to” over Greenland. Echoing previous administration statements, he said Greenland was vital for U.S. national security and that Denmark had neglected its development.

Pituffik is vital for detecting long-range, highly destructive missiles bound for the U.S. homeland, as well as picking up where submarines are lurking. “We are fully aware of our country’s strategic location,” Nielsen has said.

But the U.S. does not have to threaten or strongarm its way into mineral deals, nor boosting its Arctic presence in Greenland. Europe has spent most of its time in the last year worried about America withdrawing from Europe, not sending more military resources to NATO territory.

Greenlandic and Danish officials have been explicit in their desire for dialogue, and a 1951 defense agreement ensured a U.S. military presence in Greenland.

“This is an open door,” said Douglas Lute, a former U.S. ambassador to NATO and a retired U.S. Army lieutenant general. “There’s no reason to blast through a door, if you could simply open it and walk through,” he told Newsweek.

"If you’re bargaining for economic access, Americans already have that if they want,” said Blagden, the Exeter-based international security expert. “If you’re bargaining for security - strategic access - the European NATO states including Denmark would love to have more U.S. commitment in the North Atlantic.”

“But there's also American imperial aggrandizement, plus the fact that it means kicking NATO and kicking the Europeans is presumably an additional attraction,” Blagden said.

“American dominance in the Western Hemisphere will never be questioned again,” Trump said, shortly after U.S. forces attacked Caracas early on Saturday, whisking away the country’s leader, Nicolas Maduro, and his wife under the cover of darkness.

The U.S.’s official National Security Strategy, published in November, explicitly referenced an intention to “assert and enforce” a Trump-style addition to the Monroe Doctrine. In 1823, then-U.S. President James Monroe set out a new vision for U.S. foreign policy: European countries would leave Latin America alone, while the U.S. would cement itself as the dominant power in the Western Hemisphere.

Former President Theodore Roosevelt broadened out the Monroe Doctrine in 1904 - this became known as the Roosevelt Corollary. This change meant the U.S. would now intervene in Latin America if the leaders of individual countries in Washington’s perceived sphere of influence couldn’t manage their own affairs.

"I think that the Danes are very worried,” Aas, the former Norwegian ambassador, said. “Very, very, very very.”

Newsweek

This story was originally published January 8, 2026 at 12:00 PM.