The two plan to meet behind closed doors Friday in Alaska to discuss ‘land swapping’. What will happen this time?

The lessons of Helsinki are clear: putting Donald Trump alone in a room with Vladimir Putin is an unpredictable – and often dangerous – affair.

It was 2018 when the two leaders met at the invitation of Sauli Niinistö, the Finnish president, to discuss a collapse in US-Russia relations, accusations of elections interference, and the grinding war in east Ukraine, among other topics.

By the time he came out of the room, Trump looked dazzled by the Kremlin leader. Asked at a press conference about the conclusions of the US intelligence community that Russia had interfered in the elections, Trump said: “President Putin says it’s not Russia. I don’t see any reason why it would be.”

Fiona Hill, Trump’s senior Kremlin adviser on the US national security council, later said that she had considered pulling a fire alarm or faking a medical emergency to end the press conference.