There are two kinds of political figure who cannot be effectively satirised. One is the kind of leader who makes the satirising of leadership a crime carrying such severe penalties that nobody dares crack a disrespectful joke, let alone commit it to screen or paper. From Genghis Khan to Stalin, history’s most successful despots have always sought new ways to ensure the obedience of their subjects, but as far as I know, none has ever relied on self-deprecating humour or welcomed ridicule.