The killing of an Iranian nuclear scientist on his own doorstep sounds like an incident straight out of a juicy spy novel. Or so the Iranian authorities would have us believe. The truth behind the murder of Masoud Ali-Mohammadi may remain shrouded in mystery. Who benefits from his death? Not the alleged killers, the CIA or Mossad — unless Dr Ali-Mohammadi was such a high-level nuclear scientist that his death would decapitate the atomic weapons programme that most of the outside world believes Iran is trying to hide. Experts and intelligence agencies are sceptical that any such individual exists, and...