Trump's desire to control Greenland is not mad bluster, but why does he want it?

Greenland has been part of Denmark for 600 years, but that has not stopped the US showing a consistent interest in it.

President-elect Donald Trump has made a number of remarks about taking control of Greenland, possibly even using military force to do it – an idea that has sent shockwaves through Nato. 

He said the US needed Greenland "for national security purposes", adding he had been told that "for a long time, long before" he ran for president.

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Both France and Germany warned him not to threaten a sovereign nation. 

But why is America's next President so fixated with this huge Arctic island?

Well, Greenland is the largest island in the world and is bursting with valuable raw materials.

Equally, for America's military, it is vitally important.

Tim Marshall, author and foreign affairs expert, told BFBS Forces News "this is not some mad bluster by Trump", adding: "This is part of 21st-Century geopolitics."

He said Mr Trump wants Greenland for a number of reasons, but it is "mostly trade and military".

"On trade, as the ice melts, it's going to open up faster sea routes," he said.

But, he said, on the military side, the Greenland-Iceland-UK gap is where "the Russian submarines come… and the Russian ships come".

"The Americans want a lot more access to be able to monitor all that, but they also want access to the many, many minerals that are present," he said.

"Rare earth materials, iron, all sorts of minerals and many of them that are required for military technology – which at the moment China has the majority of access to the world's minerals."

The US military already has a large air base on Greenland – Thule Air Force Base – which was built in the 1950s and was home to bomber and transport aircraft.

Nowadays, it has been renamed as Pituffik Space Base and is used as an early warning station, one of seven around the world that America uses to detect incoming missiles.

For Nato, including the UK, that marks it as a valuable military asset. 

"The fact is that if the Americans did or could buy that territory, they would then seriously ramp up the amount of radar facilities that they have there," Mr Marshall said.

"They've only got one airbase there at the moment, they'd like a lot more up there in the High North because this is an area of growing importance to Nato.

"So, if the Americans pulled it off, big if, then that would facilitate and actually assist the UK's eyes and ears on a region that is quite close to us."

So we know Trump wants it, but what do the Greenlanders make of this?

Well in 2009 the island was granted autonomy, including the right to vote for independence through a referendum. 

Most people in Greenland do favour the idea, but they also know how heavily the island relies on Denmark's $1bn annual subsidy.

Mr Marshall said that if they did vote for independence from Denmark, the US would probably be the favoured influential force, but added there is no way China would miss the opportunity in an independent Greenland – with Russia also looking to monopolise.

Denmark's prime minister says it's up to Greenland, and Greenland alone, to determine its future. 

This is not the first time a US president has shown interest in the island.

During the Cold War, then-president Truman offered $100m in gold to buy the island, the largest in the world, but the Danish rejected the deal.

Trump tried again in 2019 to buy it, which was once more rejected by Greenland and Denmark.

Danish Prime Minister Mette Frederickson called it "absurd", with Mr Trump retaliating by cancelling a visit to Denmark. 

But with Donald Trump Jr jetting in to visit, the new administration is already showing its intent and the island is still firmly on the new president's shopping list.