Welcome to Trump’s America, The i Paper’s World Insight series presenting the sharpest, deepest thinking on an era-defining shift in history and politics, investigating how Donald Trump and his administration have changed the US and the world – and where we go from here.

• America can’t afford to retire• The US is becoming impossible to live in• The White House I worked for would have condemned this image. Trump refuses• Maga leaders want ‘traditional American families’ – but can’t stop having affairs• Sin City has lost its shine. It shows how far America has fallen• The Florida street that exposes America’s growing homophobia• Inside America’s most loyal Trump town – where people still think he’s ‘a good man’

It was the summer of 2015, and the venue was the British ambassador’s residence on Massachusetts Avenue in Washington DC. To be precise, it was the tennis court where a keenly fought doubles match was taking place. The first set had just concluded, and the players gathered at a table on which sat an ice bucket with Robinson’s Barley Water. How quintessentially British.

As drinks were consumed, Barack Obama’s deputy national security adviser turned to the ambassador and delivered a message which, while polite, could not have been more blunt: “You need to pass on to your prime minister that the president is deadly serious about the consequences of the UK reducing defence spending below 2 per cent of GDP. Don’t do it.”