What is the point of the world’s nuclear watchdog the International Atomic Energy Agency? Its task is to ensure that countries intent on developing nuclear power don’t use their programmes as cover for development of weapons of mass destruction. But is the task impossible? HARDtalk’s Stephen Sackur speaks to the new IAEA chief, Rafael Grossi. From the continued bitter arguments over Iran, to North Korea, and Saudi Arabia, is the IAEA another example of a global agency undermined by geopolitical division?