It had been a long week for US President Joe Biden.

Sweeping through England, Belgium and Switzerland, he met with G7 leaders, the Queen and his “worthy adversary” Vladimir Putin as part of a packed schedule.

The 78-year-old had been in good spirits, joking with Boris Johnson about marrying above his station, discussing geopolitics with Her Majesty and cuddling up to France’s Emmanuel Macron.

But in the stifling heat on the shore of Lake Geneva, under heavy fire from a press pack running high on adrenaline after a scuffle with Russian security, he finally lost his cool.

The question from CNN’s Kaitlan Collins was simple enough. Was he confident that Mr Putin would change his behaviour?

Clutching his suit jacket and trademark aviator sunglasses, Mr Biden was already off the podium, but he has a habit of hanging around – much to the frustration of his aides.

Turning back and walking towards the reporter with his finger raised, Mr Biden said: ‘I’m not confident he’ll change his behaviour. What the hell do you do all the time? When did I say I was confident? Let’s get it straight."

The mood had soured.

Ms Collins then asked why he thought the meeting had been "constructive".

Mr Biden said "If you don’t understand that you’re in the wrong business" and walked away.

But even as he got to the entrance of the hotel, he felt compelled to respond to another question – this time about American prisoners in Russia. He had no microphone so had to raise his voice again. The optics were terrible. 

He looked more like a footballer shouting at opposition fans after being sent off and led down the tunnel than the leader of the free world.

Mr Biden was ushered into his waiting motorcade and sped off towards the airport. By the time he arrived, just 15 minutes later, he attempted to undo the damage.

Standing by Air Force One, he made a beeline for the press pack and apologised to Ms Collins, saying: "I shouldn’t have been such a wise guy."

You know Mr Biden is in trouble when he apologises for being a “wise guy.” The last time he did it was because he told a radio show host: “If you have a problem figuring out whether you’re for me or Trump, you ain’t black.”

Mr Putin’s press conference went remarkably smoothly, putting the Russian leader firmly back on the world stage, appearing unruffled by some fierce questioning.

Where necessary he proffered a diplomatic olive branch, indicating, for example, that a prisoner swap might be possible.

But there was no giving ground on issues like cyberattacks on US targets and the Russian opposition leader, Alexei Navalny.

Fortunately, the talks between Mr Biden and Mr Putin appear to have been rather more relaxed than had been predicted.

Admittedly, the bar had been set pretty low.

But given Mr Biden’s decades of political experience, there was no chance of him embarrassing himself or the US. 

There was no repetition of JFK’s disastrous 1961 Vienna summit with Nikita Kruschev in which the Russian leader concluded that the inadequately prepared American president was not up to the job.

Neither was there a rerun of the 2018 fiasco in Helsinki when Donald Trump’s relentless determination to reset relations between Moscow and Washington saw the US president disown his own intelligence service’s warning that Russia had interfered in the election.

Divisions on the Ukraine, cyberattacks and Navalny remain.

However,  there were some modest achievements with the two sides agreeing to press ahead with arms control talks and agreeing to put their ambassadors back to work.

To use an old diplomatic cliché, the summit could best be described as “businesslike”, suggesting the two men may at least rub along, which should see a slight thaw in the relations between Moscow and Washington.

Mr Putin bore no grudges at Mr Biden having once called him a killer.

The US president, he said, was a "very balanced, professional man who is very experienced" which, given the climate leading up to the summit, could be described as fulsome praise.

Joe Biden, in turn, described the tone as "good" and "positive" which probably as good as it gets.