Security issues

Trump said on Jan 11 that the US could offer better security, as Denmark's military defense of Greenland only consists of "two dogsleds".

However, Allen, the political scientist, said if the US had "just taken control" it would have shaken existing norms.

"An attack on Greenland would (have been) a continued push toward a world order defined by regional hegemons and the power they have over their respective spheres of influence, rather than a rules-based order that the US has pushed since the end of World War II," he said.

"Such a world may have empowered the US in the Western Hemisphere, but the US would have become increasingly isolated from Europe, Africa, the Middle East, and Asia."

Steven L. Lamy, a professor emeritus of international relations and spatial sciences at the University of Southern California's Schaeffer Institute for Public Policy & Government Service, pointed out that Greenland and Denmark are members of NATO and "thus are protected by NATO member countries".

"The Danish Arctic command has planes, helicopters, patrol boats and a small contingent of troops," he told China Daily. "The dogsleds are for patrols in the northwest where there are no roads. The Danish government recently spent billions to upgrade their forces."

The reason that Trump cited growing Chinese and Russian military forces was that "the national security argument always works in the US, and Greenland was an important security concern during the Cold War", Lamy said.

"This is all part of Trump's 2025 National Security Strategy; keep foreign powers out of the Western Hemisphere; keep China out," he added.

Since 1951, the US has had a defense agreement with Denmark that allows it to expand its military presence in Greenland.

In World War II, when Nazi Germany occupied Denmark, US troops launched military and radio stations in Greenland, the BBC reported. The military remained after the war and the US currently operates Pituffik Space Base there.

The overall US military presence in Greenland is small, a few hundred, compared with upward of 6,000 forces that were once there, Allen said.

"The US could have used overwhelming force to seize Greenland despite Denmark's presence there, but the fallout from such a military attack would be disastrous for the US," he said.

"Its current security alliances would falter, come into question, or fall apart. Europe would likely retaliate with a series of measures that would exclude the US from trade with the European Union."

Allen said that while the outright acquisition of Greenland would have given the US sovereignty over the territory and the ability to accomplish some of its goals, it is not clear that sovereignty "is in any way necessary".

He said the forcible annexation of Greenland would have made it "much more difficult for the US to achieve its foreign policy goals".

Allen added that it's not just minerals that make Greenland so alluring for the Trump administration. It's in a "strategic location", as climate change "has created several new opportunities in the Arctic".

Increased navigation in the Northwest Passage and the Northern Sea Route would offer shorter shipping routes and passage from the Atlantic to the Pacific, which would help lower trade costs, Allen said.

Greenland could also be important for the US "Golden Dome" missile defense shield.

Despite the possible upgrades, the island still lacks infrastructure outside the cities where there are no large transportation hubs such as railroads or roads. Most travel is done by air.