As oil and gas commodities soar on global markets, there's another very precious commodity which leaders in the Gulf are anxiously watching: water. Much of the region has been in drought in recent years, with water supplies for some countries hitting historic lows. And in this latest conflict, water desalination plants have come under attack in Iran and Bahrain.   Guest: Kaveh Madani, Director of the UN University's Institute for Water, Environment and Health and former Deputy Head of Iran's Department of Environment Producer: Grace Stranger