Graeme Wood writes the best analysis and description of the horror of ISIS here at The Atlantic. He goes into detail about the roots of ISIS, its relationship to mainstream Islam and the ambitions of the Caliphate. He explains how ISIS combines not only a horribly literalistic interpretation of the Koran, but also how it is interlaced with radical Muslim apocalyptic visions.He sums up the whole article pretty well with this paragraph The Islamic State, also known as the Islamic State of Iraq and al-Sham (ISIS), follows a distinctive variety of Islam whose beliefs about the path to the Day of Judgment matter...