Amid tensions between President Trump and European leaders, Mr. Trump is also telling people close to him that the U.S. will withdraw from the historic Paris climate agreement, which which former President Obama helped negotiate and 195 countries signed.

It's a big move that goes beyond "abdicating leadership," according to Financial Times editor Lionel Barber.

"This is America First in caps, and it's not going to go down well amongst allies," Barber said Wednesday on "CBS This Morning." "They will look at America and say, 'Why are you pulling out when big business companies like Exxon is backing the deal?'"

Barber said such a move signals the U.S. is "going unilateral."

"You have to look at the way Mr. Trump and many people in his administration look at foreign policy. It's a zero-sum game. It's purely transactional," Barber said, questioning the signal it sends to countries like Russia and China.

Additionally, Barber said Mr. Trump's decisions are uniting Europe.

"Many commentators thought that last year when we had Brexit and then Donald Trump's victory that this would be like a populist virus spreading throughout Europe and you'd see the beginnings of the end of the European Union," Barber said. "Actually what's happened, it's not a virus. It's an antidote. Europeans actually getting closer on the back of Emmanuel Macron's victory in France, I think, in the next few months. And the more Americans appears to be going alone, then you will see greater European unity. We don't want to build a Europe against America, but America is forcing Europe to unify."

Tensions emerged between Mr. Trump and German Chancellor Angela Merkel during the president's overseas trip last week. After the G-7 and NATO meetings, Merkel said Europe could no longer rely on others – apparently meaning the U.S.

Mr. Trump escalated the feud Tuesday by tweeting: "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."

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 — Donald J. Trump (@realDonaldTrump) May 30, 2017

Barber said Mr. Trump makes an "important" point, but it might not be helpful.

"Germany's current account surplus is way too high. It's got $50 billion trade surplus with the United States. Similarly, Germany is not committing enough money to the NATO alliance," Barber said. "But the way he's going about it, I would argue particularly given a German general election campaign, is totally counterproductive."

Merkel tried to ease the dispute Tuesday by saying "transatlantic relations are of paramount importance."

