WILLIAM BRANGHAM: Welcome to the "News Hour."

America's historic allies came together at one of the world's key diplomatic gatherings today to try and chart a new future.

The Munich Security Conference has long hosted frank debates.

And, this year, European leaders confronted a world in which some of them aren't sure whether the United States will continue to help guarantee their security.

But U.S.

officials portrayed their foreign policy as a necessary correction to years of mismanagement.

Nick Schifrin is in Munich for us tonight.

NICK SCHIFRIN: Today, in Munich, world leaders displayed all the stages of grief for their old relationship with the U.S., denial, anger, bargaining, and perhaps a little depression, but, in the end, acceptance and calls to action.

FRIEDRICH MERZ, German Chancellor (through translator): A true ally takes his obligation seriously.

No one forced us into the excessive dependence on the United States that we have found ourselves in recently.

This immaturity was our own fault.

But we are now leaving this situation behind us, and sooner, rather than later.

NICK SCHIFRIN: German Chancellor Friedrich Merz spoke for many here when he admitted that Europe had relied too much on the U.S.

And French President Emmanuel Macron also spoke for many when he called for Europe to step up.

EMMANUEL MACRON, French President: In this new geopolitical environment, Europe has to become a geopolitical power.

It's ongoing, but we have to accelerate and clearly to deliver all the components of a geopolitical power, in defense, in technology, and in the de-risking vis-a-vis all the big powers in order to be much more independent.

NICK SCHIFRIN: That de-risking language used to be reserved for China.

DONALD TRUMP, President of the United States: Well, I think Greenland's going to want us.

NICK SCHIFRIN: But it's now also used for the U.S., especially since President Trump's pressure on Greenland including today at the White House.

For decades, the U.S.

has promised Europe nuclear protection, but now doubts about the U.S.

guarantee... NARRATOR: This picture is impressive evidence of the bomb.

NICK SCHIFRIN: ... has led to talk of France, promising it would use its nuclear weapons to protect all of Europe, a step it has never taken.

FRIEDRICH MERZ (through translator): In Article 42 of the Treaty on the European Union, we commit ourselves to assist each other in the event of an armed attack in Europe.

I have begun initial discussions with French President Emmanuel Macron on European nuclear deterrence.

KAJA KALLAS, Foreign Affairs High Representative, European Commission: The international order between reform and destruction.

NICK SCHIFRIN: But this is not a new world order that's established.

It's being created and debated on stage today between U.S.

Ambassador to the U.N.

Mike Waltz and Europe's top diplomat, Kaja Kallas.

MICHAEL WALTZ, U.S.

Ambassador to the United Nations: I have to push back on the premise the world on the brink, which I think was the name of this panel.

We are returning the world from the brink.

And if we have to reform multilateralism that hasn't been reformed, frankly, in 80 years, then I think that should be welcomed.

KAJA KALLAS: If we reform, then we should actually take into account the world as it currently is, where all the states are equal and also that nobody is above the law.

That's why I'm talking about accountability.

It's true that those who have the power have had different rules.

But even in jungle, animals cooperate.

And so you are better off when you work with others.