The Danish military deployed aircraft and soldiers to Greenland in January for what was publicly described as Danish-led joint military exercises, dubbed Operation Arctic Endurance. However, Denmark's public broadcaster DR, citing government and military sources, revealed the true purpose was to prepare for a potential invasion of the Arctic island by the United States under then-President Donald Trump. Danish soldiers were reportedly prepared to blow up key airport runways, and blood supplies were brought in to treat potential casualties in the event of conflict.

This extraordinary preparation was confirmed by two European officials to the Financial Times, though the Danish defence ministry declined to comment. A senior, anonymous Danish military official acknowledged that only a limited number of people were aware of the operation due to security concerns. The situation arose despite both the US and Denmark being NATO members, highlighting deep divisions between Washington and its European allies over the issue of Greenland, a semi-autonomous territory of Denmark.

Donald Trump had repeatedly expressed his desire to annex Greenland during his presidency, a proposition consistently rejected by Greenland's leader and Denmark. The DR report, based on interviews with 12 high-ranking sources in the Danish government, military, and among European allies in France and Germany, indicated that Copenhagen sought political support from Paris, Berlin, and Nordic nations. This support was intended to demonstrate strong European solidarity and encourage more joint military activities in Greenland, thereby deterring Trump.

The situation escalated significantly on January 3, when elite US forces conducted an operation to seize Venezuelan President Nicolás Maduro in Caracas. The following day, Trump told reporters he would "worry about Greenland in about two months," reiterating, "we need Greenland from a national security situation. It's so strategic," and falsely claiming, "Right now Greenland is covered with Russian and Chinese ships all over the place." A high-ranking Danish security source told DR that in light of Trump's consistent rhetoric about taking over Greenland and the events in Venezuela, they were compelled to take all scenarios seriously. A European official echoed this sentiment to the Financial Times, remarking, "After Venezuela, they [Americans] thought they could walk on water. Let's take this thing, and this country."

Shortly after these developments, a small military contingent comprising Danish, French, German, Norwegian, and Swedish soldiers was flown to Nuuk, Greenland's capital, and Kangerlussuaq, which hosts a major airport. French President Emmanuel Macron announced that this initial contingent would be reinforced with "land, air, and sea assets." DR detailed a follow-up deployment that included elite Danish soldiers and a French contingent specialized in cold-weather and mountainous warfare. Danish aircraft and a French naval vessel were also dispatched towards the North Atlantic, all under the guise of Operation Arctic Endurance.

A critical decision was made by Denmark that its soldiers would actively resist a US invasion. Soldiers were specifically trained to blow up runways in Nuuk and Kangerlussuaq to prevent US military aircraft from landing. A Danish defence source stated, "The cost to the US would have to be raised. The US would have to carry out a hostile act to get Greenland," while conceding that Danish troops would likely have been unable to repel a full-scale US attack. Later, on January 21 at the World Economic Forum in Davos, Trump, who had previously not ruled out force, stated, "I don't want to use force. I won't use force. All the United States is asking for is a place called Greenland." He subsequently expressed a desire for "immediate negotiations" to find a compromise and de-escalate the dispute. Greenland's Prime Minister affirmed the island's loyalty, stating, "We choose Denmark over US."