Roman Polanski’s new political thriller The Ghost, which is opening in the UK, is about a former British prime minister who is threatened with being hauled in front of the International Criminal Court for alleged war crimes.The title refers to a ghost writer roped in to craft the memoirs of this ex prime minister, Adam Lang. But it is the ghost of Tony Blair that haunts the fictional Mr Lang, with references to Iraq, the “war on terror”, and a much too cosy relationship with the United States.