According to Berlingske, the 1952 rule states that in the event of an invasion, “the attacked forces must immediately take up the fight without waiting for or seeking orders, even if the commanders in question are not aware of the declaration of war or state of war”.
When approached for comment, the Danish defence ministry told the newspaper: “The order on precautionary measures for military defence in the event of attacks on the country and during war, remains in force.”
European allies are holding urgent talks on how to respond to a possible US attack on Greenland, a move that experts say would probably mark the end of the Nato alliance.
“We want to take action, but we want to do so together with our European partners,” Jean-Noël Barrot, the French foreign minister, said of discussions on how Europe should respond to a US takeover of the Arctic island.
A German government source told Reuters news agency separately that Germany was “closely working together with other European countries and Denmark on the next steps regarding Greenland”.
Also on Wednesday, Barrot suggested he had received assurances from Marco Rubio, the US Secretary of State, that Washington was not planning an “invasion”.
“I myself was on the phone yesterday with US Secretary of State Marco Rubio ... who confirmed that this was not the approach taken ... he ruled out the possibility of an invasion [of Greenland],” said the French Foreign Minister.
Rubio also briefed US politicians that threats against Greenland do not signal an imminent invasion, and that the goal is to buy the island, sources told the Wall Street Journal (WSJ).
The WSJ report and Rubio’s assurances appeared to contradict Karoline Leavitt, Trump’s press secretary, who said on Tuesday that military action was “always an option”.
At the same time, The Washington Post reported on Wednesday that US officials were increasingly discussing a takeover of Greenland with their European counterparts as a “concrete” possibility.
A senior European diplomat told the newspaper that there had been a marked shift in tone on the issue in recent days.
Dominique de Villepin, the former French Prime Minister, has warned that if the US did invade Greenland, it would become an “enemy” of Europe’s Nato members.
“In no case should Europe accept any damage to European sovereignty,” Villepin told Bloomberg TV, as he stressed that a case of one Nato member attacking another was “unprecedented”.
“And of course if Donald Trump goes forward, the status of the US will go from adversary or rival to the one of enemy,” Villepin said. “It’ll be a huge historical change.”
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