Fierce fighting in northern Iraq continues daily between the Islamic State, IS rebel army, Iraq's Kurdish Peshmerga fighters and the Iraqi national army. For Our World, Yalda Hakim has travelled to the region to assess how the brutal treatment of Iraq's Christian and Yazidi minorities at the hands of IS, could be a terrifying precursor for what might lie ahead in Iraq if IS gains the upper hand in the battle for control of what is fast becoming a failed state