Editorial: The US president’s latest spurious outpourings – not least his suggestions that Volodymyr Zelensky is a ‘dictator’ and that Kyiv is to blame for Russia’s invasion – have further perturbed European leaders. It now falls to Sir Keir Starmer during his visit to Washington next week not only to set him straight, but also to beat Vladimir Putin to the role of most trusted ‘Trump Whisperer’