German Chancellor Angela Merkel has said that Europe needs to “reposition” itself in a changed world as she welcomed European powers’ unity over Iran.

Mrs Merkel said in an interview with Germany’s daily Sueddeutsche Zeitung that Europe needs “forward-looking” arguments and stressed that “simply pointing to seven decades of peace is no longer enough to justify Europe”.

Before European Parliament elections on May 23-26, she said there is “no doubt that Europe needs to reposition itself in a changed world,” in which some post-Second World War certainties no longer hold.

She acknowledged that Europe appears weak in the stand-off over Iran because, with the dollar’s role as a leading global currency, it struggles to counter US sanctions as it tries to salvage the nuclear deal with Tehran. But she said that Europe has also made progress.

“Germany, France and Britain are taking a different approach from the US on the question of the Iran agreement,” she said. “For all our other differences, we even have common interests here with Russia and China.”

“That Europe is no longer divided on this important question as it was in the Iraq war is a value in itself,” Mrs Merkel added. Germany and France opposed the US-led war in Iraq in 2003, while countries including Britain and Poland supported Washington.

However, she added that Europe has a “realistic” assessment of its capabilities and “must strengthen them for the future”. She said it is making good progress on defence cooperation.

Asked what effect global challenges from China, Russia and the US are having on Europe, she said that they are making the EU find common positions, which is often difficult “but we succeed” — for instance in policy on Ukraine and Africa. She conceded that “our political strength doesn’t yet match our economic capabilities”.

Next week’s EU elections are expected to boost populist parties at the expense of the political centre.

Asked how much populism the 28-nation EU can take before it collapses, Mrs Merkel said that “this is indeed a time when we have to fight for our principles and fundamental values”.

European leaders will decide “how far to let populism go, or whether we ultimately have the will to take on joint responsibility.”

“So far, we have always managed to do so,” she added. So as not to endanger Europe, she said, “everyone needs to put themselves in others’ shoes, to be willing to compromise, remain honest and always treat each other carefully.”