All his adult life, Colonel Soren Knudsen stepped forward when his country called. And when its allies did.

He fought alongside US troops, notably in Afghanistan, and for a time was Denmark’s most senior officer there. He counted 58 rocket attacks during his duty.

“I was awarded a Bronze Star Medal by the United States and they gave me the Stars and Stripes. They have been hanging on my wall in our house ever since and I have proudly shown them to everybody.”

Then something changed.

“After JD Vance’s statement on Greenland, the president’s disrespect for internationally acknowledged borders, I took those that Stars and Stripes down and the medal has been put away,” Soren says, his voice breaking a little.

This week before Congress, the US president doubled down on his desire to seize the world’s biggest island: Greenland, an autonomous territory of the Kingdom of Denmark.

“My first feeling was that it hurts, and the second is that I’m offended,” Col Knudsen laments.

I meet him in the first weeks of his retirement outside Denmark’s 18th Century royal residence, Amalienborg Palace in the heart of Copenhagen.

Abruptly, pipers strike up and soldiers stream by.

Today’s Changing of the Guard comes at a time when the Trump administration has not just tweaked but defenestrated most assumptions around US-European security that have held fast for 80 years.

“It’s about values and when those values are axed by what we thought was an ally, it gets very tough to watch.” Soren says with his American wife Gina at his side.

“Denmark freely and without question joined those efforts where my husband served,” she says.

“So it comes as a shock to hear threats from a country that I also love and to feel that alliance is being trampled on. This feels personal, not like some abstract foreign policy tactic.”

Soren has not given up all hope though.

“It’s my hope and my prayer that I will one day be able to put [the flag] back on the wall”, he confides.

There’s no sign his prayers will be answered soon.

Greenland, an autonomous territory of the Kingdom of Denmark, goes to the polls next week with all the main parties backing independence at some point in the future.

A takeover by Donald Trump – potentially by force – is not on the ballot paper.

Not far from the royal palace stands Denmark’s memorial to its soldiers lost in recent battle.

Carved on the stone-covered walls are the names of those killed alongside their Western allies.

The section honouring the fallen in the US-led invasion of Afghanistan is particularly sizeable.

Denmark lost 44 soldiers in Afghanistan, which as a proportion of its less than six million population, was more than any other ally apart from the US. In Iraq, eight Danish soldiers died.

This is why the president’s words sting so much.

One man very well placed to consider what Trump’s ambitions for Greenland actually amount to is Anders Fogh Rasmussen.

“President Trump’s declaration of intention to maybe take Greenland by force is very similar to President Putin’s rhetoric when it comes to Ukraine,” he tells the BBC.

The former prime minister of Denmark and ex-secretary general of the Nato alliance argues this is the moment Denmark and the rest of Europe must step up to better protect itself if the US is not willing to.

“Since my childhood, I have admired the United States and their role as the world’s policeman. And I think we need a policeman to ensure international law and order but if the United States does not want to execute that role, then Europe must be able to defend itself, to stand on its own feet.”

Fogh Rasmussen doesn’t though believe the policeman is about to turn felon.

“I would like to stress I don’t think at the end of the day that the Americans will take Greenland by force.”

President Trump first talked about a Greenland takeover in his first term of office before returning to the theme at the start of this year.

But now, after blindsiding supposed allies with his latest moves on Ukraine, tariffs, as well as the Middle East, Denmark is urgently trying the assess the true threat.

For many younger Danes, control of Greenland is plain wrong – an unfathomable colonial hangover.

It doesn’t mean they want it handed straight over the US instead.

“We do have connections to Greenland,” says music student Molly. “Denmark and Greenland are quite separated I would say but I still have friends from there so this does affect me quite personally.”

“I find it really scary,” says 18-year-old music student Luukas.

“Everything he sees, he goes after. And the thing with the oil and money, he doesn’t care about the climate, he doesn’t care about anyone or anything.”

His friend Clara chips in that Trump is now so powerful he can “affect their day-to-day life” from thousands of miles away, in what is an era of unprecedented jeopardy.

In light of President Trump’s suspension of military aid for Ukraine and his deep reluctance to fund Europe’s security, Denmark has been at the heart of the drive to boost defence spending across the continent.

The country has just announced it will allocate more than 3% of its GDP to defence spending in 2025 and 2026 to protect against future aggression from Russia or elsewhere.

Meanwhile, security analyst Hans Tino Hansen stands in front of a huge screen in what he calls his “ops room”, at his Copenhagen headquarters.

“This map is where we update on a daily basis our threat picture based on alerts and incidents all over the world,” says Hans, who has been running Risk Intelligence for the past 25 years.

As part of Denmark’s increased defence spending, it’s bolstering its strength in the “High North” with an extra two billion euros announced in January and three new Arctic naval vessels and investment in long-range drones.

Hans believes Arctic security can be tightened further, not by an American takeover – but with new deals that restore US influence.

“If you make more agreements, both on defence and security, but also economic ones and on raw materials, then we are more or less going back to where we were in the 50s and 60s.”

But the story stretches further back than the mid-20th Century.

“If you look at this globe, Greenland is the most centrally located place on Earth,” says world-renowned geologist Prof Minik Rosing, gesticulating in his wood-panelled office.

The serenity of his room reflects the temperament of a man who grew up in a settlement of just “seven or eight people” in the Nuuk fjord of the island.

But a key reason his homeland is now coming under increasing scrutiny from outsiders is the rich mineral deposits beneath the Arctic ice.

We’ve seen how Ukraine’s natural resources have caught President Trump’s eye in much the same way.

“All these minerals that they talk about like rare metals, rare earth elements – they are actually not rare. What is rare is the use of them,” he reasons.

Prof Rosing says the vastness of Greenland and the lack of infrastructure are just two elements why the island may not be the cashpoint some Americans are hoping for.

“They are a minuscule part of the mining industry and the economy of extracting them is very uncertain, whereas the investment to start extracting is very high. The risk of the investment is too high relative to the potential gain.”

The current Greenlandic government says there will be a vote on independence at some point following next week’s election.

Although surely unintentional, President Trump’s designs on the island have shone a light on a desire found among the Inuit to finally break free from 300 years of Danish control.

But Prof Rosing believes, despite all the latent mineral wealth, his fellow Greenlanders are in no hurry to forego the annual block grant of the equivalent of £480m (€570m) it receives from Copenhagen.

This accounts for easily more than half of the island’s public budget.

“People talk about health services, schools, the next outboard engine they want on their boat and what is the price of gas and all of these things that normal people do,” he says.

“It’s not like they stand up with a big knife, wave it in the air and shout independence, independence.”

In terms of Trump’s apparent obsession with taking Greenland, Fogh Rasmussen fears there may be a troubling conclusion to be drawn.

One that would render the Danes unable to do business with a man whose view on territorial integrity is so wildly incompatible from theirs.

“I understand very well the American strategic interest in the minerals, but when it comes to mining in Greenland, they have shown no interest,” he says.

“That leaves me with the concern that maybe it’s not about security, maybe it’s not about minerals, maybe it is just a question of expanding the territory of the United States.

“And that’s actually a point where we are not able to accommodate President Trump.”

Additional reporting by Kostas Kallergis