On August 18th Volodymyr Zelensky, Ukraine’s president, will enter the White House to meet Donald Trump and discuss ending the war in Ukraine. For Mr Zelensky it is a perilous moment. Since Mr Trump met Vladimir Putin, Russia’s president, in Alaska on August 15th, the American president has put intense pressure on Mr Zelensky, stating that he could “end the war with Russia almost immediately, if he wants to”. The leaders of Britain, France, Germany, Italy, Finland and the European Union fear the White House will sell out Ukraine and Europe, and are rushing to Washington to support Mr Zelensky. “Never had so many European leaders at one time,” wrote Mr Trump. “My great honour to host them!”