An article in the Atlantic , strangely bearing a dateline of next month, gives us a glimpse into the theology of ISIS- and how it differs strongly from the Muwahiddun of Al Qaida. Salafism- literally the "Faith of our pious forefathers", by which they mean the army and generals of Mohammed, is very much the attempt to roll back 1400 years of Islamic history to a form of government and religion that hasn't existed since the 7th century A.D. While Al Qaida was aiming for this all along, nobody in Bin Laden's circle expected to see a new Caliph for several centuries. Salafism, on the other hand, is a radical form of Sunni Islam which entered a branch of Al Qaida after bin Laden's death with the teachings of Zarqawi, that insists that many sins are really signs of apostasy- and that apostasy is worthy only of death: Maqdisi wrote to his former pupil that he needed to exercise caution and “not issue sweeping proclamations of takfir” or “proclaim people to be apostates...