Peter Mandelson’s flaws were mistaken for credentials to represent Britain in the court of a rogue president Peter Mandelson’s flaws were mistaken for credentials to represent Britain in the court of a rogue president Y ou can’t kill something that is already dead. New details about Peter Mandelson’s disastrous appointment as Britain’s ambassador to Washington can trigger more paroxysms of outrage in Westminster. They can sharpen the pitch of opposition calls for the prime minister to resign.