President Obama refused to take David Cameron’s telephone calls at key moments and was nicknamed “Spock” for his detached, deliberative manner by Downing Street staffers.
According to Sir Anthony Seldon’s biography, No 10 believed that the president gave an impression of lacking warmth and collegiality.
Mr Cameron often found him “too rational and considered” and, within the Foreign and Commonwealth Office, he was nicknamed Spock, the Vulcan from Star Trek, the book says.
It says that Mr Obama exhibited his indecision over Libya when Mr Cameron and the then French president Nicolas Sarkozy wanted military action to oust Colonel Gaddafi in 2011.
“He won’t take our calls because he doesn’t know where he stands. It’s not very impressive,” one Downing Street aide is quoted