Arab leaders have called the situation in Iraq the most dangerous in its history and a threat to overall regional security. Jihadist fighters from the Sunni militant group Isis - deemed too extremist even by Al Qaeda - have seized control of a big chunk of Iraqi territory, including the country's second biggest city Mosul. Thousands have fled their homes triggering a humanitarian crisis. Iraqis have been urged to take up arms against the militants, increasing worries of a sectarian bloodbath. HARDtalk speaks to Tariq al-Hashimi - the fugitive former Vice-President of Iraq. What should Sunni leaders like him do to stop the country fragmenting?