The first cracks in US-UK security co-operation are appearing as tensions between Donald Trump and Sir Keir Starmer over Iran shake working relationships between diplomats, officials and military personnel.
The US president’s recent public criticism of the UK prime minister — deriding Starmer as “no Winston Churchill” and a leader who has tried to “join wars after we’ve already won” — has already had a chilling effect behind the scenes, according to people familiar with the situation.
Some of this has been a feature since Trump returned to the White House. The handful of American officials seconded to UK government departments are increasingly being asked to leave meetings when sensitive information is discussed, in contrast to a more permissive approach previously, one of the people said.