It was an unusual day at the Nato summit on Tuesday as Donald Trump faced a rare show of public resistance from French President Emanuel Macron, the leader of one of America’s closest allies.

The two world leaders, who had been trying to forge a close friendship in the past years, clashed on the world stage in an uncomfortable atmosphere.

Having been insulted by President Trump in the lead-up to their meeting, President Macron did not hesitate to push back against the US leader, interrupting him at times, correcting his mistakes, and speaking in French sometimes so that Mr Trump had to lean over towards a translator to understand what was being said.

At one point the French leader even snapped at his US counterpart “Let’s be serious!” after Mr Trump joked about sending Isis fighters back to France.

Mr Macron also confronted President Trump over the claim that the Islamic State has disappeared from Syria and the Middle East, telling him: “It’s not done yet. I’m sorry to say that.”

Trump makes surprise Thanksgiving visit to US troops in Afghanistan Show all 10 1 /10 Trump makes surprise Thanksgiving visit to US troops in Afghanistan Trump makes surprise Thanksgiving visit to US troops in Afghanistan Donald Trump laughs with US troops after serving them Thanksgiving dinner at Bagram airbase during a surprise visit to Afghanistan AFP via Getty Images Trump makes surprise Thanksgiving visit to US troops in Afghanistan It was the president's first visit to Afghanistan AFP via Getty Images Trump makes surprise Thanksgiving visit to US troops in Afghanistan As is traditional with senior politicians, he was happy to help serve the troops – his vice-president Mike Pence did the same for US forces in Iraq a few days earlier AFP via Getty Images Trump makes surprise Thanksgiving visit to US troops in Afghanistan Mr Trump gets stuck in. He told troops he had only been able to have a mouthful of mashed potatoes – and no turkey – before being dragged off to address them AFP via Getty Images Trump makes surprise Thanksgiving visit to US troops in Afghanistan The president applauds as his Afghan counterpart Ashraf Ghani addresses troops AFP via Getty Images Trump makes surprise Thanksgiving visit to US troops in Afghanistan Mr Trump said that he was willing to restart talks with the Taliban REUTERS Trump makes surprise Thanksgiving visit to US troops in Afghanistan He told US troops: "The Taliban wants to make a deal. And we are meeting with them and we say it has to be a ceasefire and they didn't want to do a ceasefire and now they want to do a ceasefire, I believe. It will probably work out that way." AFP via Getty Images Trump makes surprise Thanksgiving visit to US troops in Afghanistan Mr Trump was accompanied on his trip by his national security adviser, Robert O'Brien. While it was his first trip to Afghanistan since becoming president in January 2017, he has been to a warzone once before when he visited troops in Iraq AFP via Getty Images Trump makes surprise Thanksgiving visit to US troops in Afghanistan The president told troops that he had flown 8,331 miles to be there to tell them the US has never been stronger. He said: "There is nowhere I'd rather celebrate Thanksgiving." AFP via Getty Images Trump makes surprise Thanksgiving visit to US troops in Afghanistan Mr Ghani and Mr Trump holding talks at Bagram airbase. Tens of thousands of Afghan civilians and more than 2,400 American service members have been killed since America's longest war began 18 years ago AP

For the young and ambitious Macron who had been trying to flatter the US president the past few years, it looked like he was fed up and started calling it like he saw it.

The unprecedented confrontation came against the background of Nato and European leaders discussing how to deal with the US and Trump, whether America is really stepping back from the world, and if Europe needs to step up in its own defence.

Even before the summit started, Trump announced new tariffs on French products, escalating a trade war with one of America’s closest allies.

Experts say Mr Trump’s policies have been weakening Nato.

Joseph Cirincione, president of the Ploughshares Fund in Washington, told The Independent that Trump sees America’s closest allies as economic rivals that he would rather confront one-on-one.

“He may share Vladimir Putin’s agenda of dissolving Nato. His comments on Macron are part of his standard pattern of accusing his opponents of doing what he, himself, is guilty of,” he said.

Mr Cirincione believes there needs to be fresh thinking in Nato and the US need to rebalance defence spending, but neither Trump nor Macron know how to do it.

Another major disagreement seems to be on Turkey, with Mr Macron asking rhetorically how it is possible to be a member of Nato and buy Russia’s S400 missile systems. “Technically it is not possible,” he answered his own question adding that “They decided not to be compliant with Nato.”

And when Mr Trump tried to blame Barack Obama, saying that Turkey did want to buy Patriot Missiles, Macron corrected him again saying that is not the case.

Benjamin Friedman, policy director at Defence Priorities in Washington, said it is funny that Trump is posing as a defender of Nato after Macron called it brain dead: they seem to have reversed roles.

“The fact of the matter is that both of them, for all their rumbling in different ways about Nato, are defenders of its status quo. Neither is pushing big changes. Trump talks about shaking down allies for more money, but adds US forces to Europe and settles easily. Macron complains about its purpose, but hasn’t suggested any dramatic moves to replace it,” Mr Friedman told The Independent.

Mr Trump also suggested that the European Union was partially formed to “take advantage” of the United States, adding that a lot of people didn’t know that and he “exposed it”.

Trudeau, Macron and Johnson caught on camera making fun of Trump

The Trump-Macron rift is not just a verbal clash. It is rooted in policies and world-views.