Britain's Prime Minister Keir Starmer promised to protect British business.Keir Starmer has issued a bleak warning about the real-term impact of Donald Trump’s tariffs, saying “the world as we knew it has gone”.Writing after the US president slapped 10% tariffs on British exports going to the States – on top of a 25% levy for cars and steel products – the prime minister said the UK must “rise to meet the moment”.“The new world is less governed by established rules and more by deals and alliances,” Starmer wrote in The Sunday Telegraph.The 10% tariff is what Trump has described as a “base rate”, and comes after Downing Street has spent months trying to work on the UK’s special relationship with the US.Nodding to the UK’s decision not to immediately retaliate with reciprocal tariffs – like China has, hitting the States with a 34% levy – the PM said: “Nobody wins from a