Something in Europe has snapped. Donald Trump doubled down again on Monday, in his insistence that the US needs Greenland for national security reasons.

Is he prepared to use force to seize it, journalists asked him? No comment, said the president, sending chills down the spine of Greenland's anxious inhabitants. Again.

Greenland is a semi-autonomous territory of Denmark - a member of the EU and of Nato. President Trump is now leaning heavily on Denmark's allies in both those organisations to abandon Copenhagen and let the US take control of Greenland, or face punitive taxes on all their exports to the United States.

It's a horror scenario for European economies, which are already in the doldrums. Especially those reliant on exporting to the US, like Germany's car industry and Italy's luxury goods market.

On Monday Germany's finance minister said, we will not allow ourselves to be blackmailed after an emergency meeting with his French counterpart.

The Trump threats landed like a slap in the face of European governments, who (separately, in the case of the EU and the UK) had only just settled tariff deals with the US president last year.

All of a sudden, the softly-softly approach to Trump that Europe's leaders had clearly favoured since he returned for a second term to the White House seems to have passed its sell-by date.

It's too early to read the last rites on transatlantic relations altogether but the EU, at least, is hoping to approach the US president in Switzerland this Wednesday at the Global Economic Forum speaking softly, while carrying a big stick to paraphrase a former US president.

European leaders are telling President Trump they'll support him in prioritising Arctic security, so there's no need for him to go it alone over Greenland.

But amidst echoed sentiments from officials that they would have to be prepared for any fallout should Trump proceed with what they have dubbed his Greenland tariffs, the stakes appear to be escalating quickly.

As the situation develops, the EU aims to negotiate a path that preserves alliances while asserting its stance on sovereignty and trade—balancing diplomacy and strength in a complex and unsure international landscape.