President Donald Trump at the final presidential debate with Democratic presidential nominee Joe Biden at Belmont University in Nashville, Tennessee, on October 22, 2020. REUTERS/Jim Bourg/Pool Exclusive: Sir Nigel Sheinwald, Britain's former ambassador to the US, tells Business Insider that President Trump will try to 'take advantage' of the UK's weakness after Brexit if re-elected. Boris Johnson enjoys a warm personal relationship with the president, but the White House has adopted an increasingly bullish attitude towards the UK in recent months, Sheinwald said. Sheinwald said: 'The mood [from Washington to the UK] has become increasingly hectoring and domineering.