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 because of their sins.” The distinction between apostate and sinner may appear subtle, but it is a key point of contention between al-Qaeda and the Islamic State.
Denying the holiness of the Koran or the prophecies of Muhammad is straightforward apostasy. But Zarqawi and the state he spawned take the position that many other acts can remove a Muslim from Islam. These include, in certain cases, selling alcohol or drugs, wearing Western clothes or shaving one’s beard, voting in an election—even for a Muslim candidate—and being lax about calling other people apostates. Being a Shiite, as most Iraqi Arabs are, meets the standard as well, because the Islamic State regards Shiism as innovation, and to innovate on the Koran is to deny its initial perfection. (The Islamic State claims that common Shiite practices, such as worship at the graves of imams and public self-flagellation, have no basis in the Koran or in the example of the Prophet.) That means roughly 200 million Shia are marked for death. So too are the heads of state of every Muslim country, who have elevated man-made law above Sharia by running for office or enforcing laws not made by God.
Following takfiri doctrine, the Islamic State is committed to purifying the world by killing vast numbers of people. The lack of objective reporting from its territory makes the true extent of the slaughter unknowable, but social-media posts from the region suggest that individual executions happen more or less continually, and mass executions every few weeks. Muslim “apostates” are the most common victims. Exempted from automatic execution, it appears, are Christians who do not resist their new government. Baghdadi permits them to live, as long as they pay a special tax, known as the jizya, and acknowledge their subjugation. The Koranic authority for this practice is not in dispute.
Of course, those Christians who fail to pay the tax are executed. Captured foreign soldiers are executed. Captured foreign citizens are attempted to be ransomed to add to the Caliph's wealth, and when such ransom is not forthcoming, are executed.
They rejoiced in taking the largely rural town of Dabiq, Syria- because they imagine that to be the very fields of Armageddon, and they want to be prepared when the Pope's Army comes to meet their forces, in a battle that supposedly the Prophet himself predicted they would win. My suggestion, if the Pope does raise up a new crusade, is to start in Libya, not Turkey, and shock the heck out of them by going counter clockwise around the Mediterranean.
One slightly positive note. I made much about the practice of Sola Jihad of the Muwahiddun, their insistence that Allah is the only ruler, and their strong theological resemblence to American Protestant Christian Fundamentalists. Out of fundamentalism, though, came the Dispensationalists, the Jehovah's Witnesses, the Branch Davidians, and the Davidian Guard of the Westboro Baptists. So to with this new Caliph, we have a return to Offensive Jihadism, a primitive form of the Preemptive Strike of modern Nuclear War theory; where it is part of the duty of the Caliph to challenge the borders of his more secular, less Islamic neighbors.
That doesn't sound like good news until you realize the tactics of this "Caliph of Baghdad", al Baghdadi, are dictated by his understanding of the bloody 7th century expansion of Islam- and that means that for modern forces able to reason, his movements are entirely predictable; they are in fact quite able to be defended against should secular forces, Islamic or Christian, choose to do so. Which is also as predicted- for after the sack of Istanbul, it is predicted that a great anti-Christ will arise out of Shi'ite Iran, to kill off everybody in the Caliphate down to the last 5000 soldiers, who will hole up in Jerusalem before being destroyed.