Executive Summary

• Trump refuses to rule out military force to compel Greenland to become part of the US.
• The President said he would invoke tariffs against nations opposing the annexation, raising fears in Europe that these statements are more than a negotiating tactic.
• Military takeover in Greenland would have significant second order effects and could be telegraphed by other actions.

The Big Question: Really?

The answer: Maybe. Trump has repeatedly failed to discount a military takeover, emboldened by his success in bombing Iran and capture of President Maduro.  Greenland is very different. Denmark has been a staunch ally of the US since 1801 and has not waivered in support of US policy and military actions. But Trump is not bound by the past.

In Afghanistan Denmark sent 18,000 troops from 2002-2021 for action in the Helmand providence.  Denmark has spent scores of billions on US equipment be as close to the US as possible. The last deal was $3.7B for AMRAAMs and integrated air / missile defense. In response to Trump’s threatening posture, European nations have committed small troop deployments to Greenland to show support for the Danish position.

A military strike/invasion to “take” Greenland would not likely be a surprise.  An invasion is, by definition, an Act of War against Greenland and Denmark (both NATO members) and would elicit an Article 5 response (an attack on one is an attack on all) from NATO, whose military commander is an American.  This would make all US military personnel in Europe, approximately 84,000 to 90,000 troops, de facto enemy combatants against NATO.  These troops, and their over 120,000 dependents would be subject to host nation decisions on their status, which could range from isolation on their host bases to internment by local authorities.  Due to a lack of on-base housing, a majority of US families live on the local economy.  Since these bases are not US territory, but are the property of the host nations, they do not have a significant defense capability beyond patrolling their perimeters and cooperation with local law enforcement and security agencies.  The effect would be profound and mark the end of military cooperation as well as the end of NATO.

In recent months the administration has reduced some troop levels in Europe.  To avoid having US civilians interned in host nations, the US might call for removal of all non-essential personnel (e.g., families) from Europe if an invasion of Greenland is expected or imminent.  This would be a significant signal to Europe that the US plans a military strike.

An invasion would likely be contested by Greenlanders and NATO.  Trump might believe it would be bloodless (like the annexation of Austria by Germany in 1938) but the probability of that is low.  Whether through intentional action against US troops invading Greenland, or through an accidental incident, the chances of innocent civilians being killed or injured is substantial.  This could escalate quickly because the population is intensely against being “taken” by the US, and most want independence from Denmark as well.

Due to the weather in that part of the world, a winter invasion is difficult, though possible, and would require a substantial force to secure the capital and major ports, with supply lines over water since the US space base is in the Northern part of the island.  The US assumed that Iraqis would “welcome us with open arms” in 2003.  That proved to be a costly assumption by the Bush Administration.  With potential bloodshed on the island and US troops and civilians in Europe at risk, this is a crucial decision for the President.