... Individuals susceptible to recruitment “might have lost their jobs, might have had a mental health crisis, might have just concluded that however hard they’ve tried, they never belong," said Edmund Fitton-Brown, a former British diplomat who led a U.N. team that monitors Islamic State and al Qaeda. The main appeal of Islamic State is its determination to establish a Sunni Muslim “caliphate” ruled by Islamic law, unlike the Taliban, which “has sold out to Afghan nationalism,” or al Qaeda, members of which have cooperated with Iran’s Shiite Muslim-run government, he said.”