US Secretary of State Marco Rubio said transatlantic ties faced a “defining moment” in a rapidly changing world but struck a warmer tone ahead of the Munich Security Conference on Friday after a year of unprecedented upheaval.

At the same gathering of top security officials last year, Vice President JD Vance had attacked European allies, triggering a series of confrontations, with the US seemingly set on dismantling much of the international order it helped to build.

In response, Washington’s partners have been pushing to chart a more independent course while preserving the basis of the alliance, as they face myriad threats from Russia’s war in Ukraine to massive ructions in global trade.

“I think it’s at a defining moment ... the world is changing very fast right in front of us,” Rubio said before departing for Munich.

“The Old World is gone, frankly, the world I grew up in, and we live in a new era in geopolitics, and it’s going to require all of us to re-examine what that looks like and what our role is going to be,” he said.

“(The US is) deeply tied to Europe, and our futures have always been linked and will continue to be,” said Rubio, who is a potential rival to Vance for the 2028 US presidential race. “So we’ve just got to talk about what that future looks like.”

‘Wrecking-ball politics’ threaten alliance

This year’s meeting comes against a backdrop of multiple conflicts, including wars in Ukraine, Gaza and Sudan.

Transatlantic ties have long been central to the Munich Security Conference, which began as a Cold War forum for Western defence debate. But the unquestioned assumption of cooperation that underpinned it has been upended.

Wolfgang Ischinger, the former German diplomat who heads the forum, spoke this week of “wrecking-ball politics” in which “sweeping destruction – rather than careful reforms and policy corrections – is the order of the day”.

Underscoring the damage, a YouGov poll on Friday of the six largest European countries showed favourability towards the US in Europe hitting its lowest since tracking began in 2016.

The latest figures are broadly comparable to – and in some cases higher than – the perceived threat from China, Iran or North Korea, although behind Russia, YouGov said.

US President Donald Trump has toppled Venezuela’s leader, threatened other Latin American countries with similar military action, imposed tariffs on friends and foes alike and talked openly about annexing Greenland from fellow NATO member Denmark - a move that could effectively end the alliance.

“No one in Europe or in the United States wins from any kind of conflict between old allies,” said Danish Prime Minister Mette Frederiksen, who said she would meet Rubio in Munich.

“So we must do what we can to keep the Americans close to us, but this is a new world disorder that we live in. And that is why the most important thing for us Europeans is that we arm ourselves as quickly as possible.”

The Trump administration’s harsh new tone, including a dire warning that Europe faces “civilisational erasure”, has shaken its allies, which have pledged to step up spending on their own militaries after decades of neglect.

Europe’s dependence on US military support will take years to undo, however, leaving it vulnerable as the standoff with Russia over the Ukraine war persists.

Germany’s foreign minister said on Friday that recent comments by US officials have caused irritation within NATO.

“This alliance is also under pressure. There is alienation, there is irritation about some of the things we hear from Washington. We need to talk about this here together,” Johann Wadephul told German broadcaster ARD.

In another striking sign of the shifting rhetoric, the head of Germany’s industry association BDI, Peter Leibinger, said in Munich that Europeans had to prepare their defence sector “with, without and possibly against Washington”.

German Chancellor Friedrich Merz will open the conference with a speech on Friday afternoon, while around 70 heads of state and government and more than 140 ministers are expected under tight security in Munich.

Prominent attendees include Chinese Foreign Minister Wang Yi, Ukrainian President Volodymyr Zelenskiy and French President Emmanuel Macron, who this week warned: “We have the Chinese tsunami on the trade front, and we have minute-by-minute instability on the American side.”