German Chancellor Angela Merkel said she thinks the post-World War II global order as we know it is over — and grouped the United States with China and Russia as adversaries of Europe.

"There is no doubt that Europe needs to reposition itself in a changed world," Merkel told Süddeutsche Zeitung in an interview, shared with The Guardian. "The old certainties of the postwar order no longer apply."

Less than three years ago, Germany was one of the US's closest allies, and Merkel was working harmoniously with President Barack Obama.

President Donald Trump, however, frequently insulted Merkel over the 2015 refugee crisis and has clashed with her on multiple occasions over NATO's budget and the US's trade deficit with Germany.

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German Chancellor Angela Merkel said in a recent interview with the German newspaper Süddeutsche Zeitung that she thinks the postwar global order built over seven decades is over — and grouped the United States with China and Russia as rivals of Europe.

Merkel, who's been Germany's chancellor since 2005 and was the leader of the center-right Christian Democratic Union party from 2000 to 2018, said in the interview, which was shared with The Guardian, that the traditionally strong diplomatic and military alliance between the European Union and the United States forged after World War II is now on shaky footing.

"There is no doubt that Europe needs to reposition itself in a changed world," Merkel said. "The old certainties of the postwar order no longer apply."

According to The Guardian, she added that the US, Russia, and China "are forcing us, time and again, to find common positions."

Read more: Trump offends Europe with diplomatic snub revealed at George H.W. Bush's funeral

Merkel said she thinks the rise of right-wing populism — which many scholars have cited as the force behind seismic geopolitical events like Britain's exit from the EU, the election of US President Donald Trump, and the rise of populist leaders throughout Europe — has fundamentally shifted the global order of alliances and leaves Europe and its political and economic union on the defense.

"Simply stating that we've enjoyed seven decades of peace is no longer enough to justify the European project," she said. "Without forward-looking arguments to justify Europe, the European peace project would also be in greater jeopardy than one may think."

Less than three years ago, Germany was one of the US's closest allies, and Merkel was working harmoniously with President Barack Obama. Merkel and Obama not only shared perspectives on various foreign and economic policy issues but were close friends.

During his 2016 presidential campaign, Trump accused Merkel of "ruining Germany" by allowing Syrian refugees to resettle there, and he tried to smear his Democratic opponent, Hillary Clinton, by comparing her to Merkel.

And over the past year and a half, Trump has consistently criticized Germany over trade and accused it of not contributing fairly to NATO's budget, leading to several tense interactions with Merkel, who has decried Trump's cozy relationship with Russia.

Read more: 11 photos show how close Merkel was with Obama, and how different things are with Trump

In May 2017, Merkel made a subtle jab at Trump, saying at a campaign event: "The times in which we could fully rely on others are partly over. I have experienced this in the last few days. We Europeans really have to take our destiny into our own hands."

Trump hit back on Twitter a few days later, writing: "We have a MASSIVE trade deficit with Germany, plus they pay FAR LESS than they should on NATO & military. Very bad for U.S. This will change."

Germany's ties to the US military date back to the end of World War II, and roughly 33,000 US troops are based in the country to assure European security against adversaries like Russia.

Merkel said that in the face of the rising geopolitical influence of populism and the military prowess of China and Russia, European nations banding together to defend liberal values and principles is increasingly important.