Can there be a negotiated way out of the high stakes stand-off between Iran and the West over the Islamic Republic's nuclear ambitions? A new round of talks is planned for later this month but the basic facts haven't changed, Iran's enrichment programme gets ever more sophisticated, international sanctions on Tehran bite deeper and the warnings from the West grow darker. Stephen Sackur’s guest on Hardtalk is a former Iranian negotiator on the nuclear issue, Hossein Mousavian. Does diplomacy have a chance?