What does Saudi Arabia have to do with the terrorist ISIS/ISIL/IS/xyz army? EVERYTHING!

Below the first few paragraphs from an article at HuffPo by Alastair Crooke, a Former MI-6 agent and the Authorof "Resistance: The Essence of Islamic Revolution"

The dramatic arrival of Da'ish (ISIS)  on the stage of Iraq has shocked many in the West. Many have been perplexed -- and horrified -- by its violence and its evident magnetism for Sunni youth. But more than this, they find Saudi Arabia's ambivalence in the face of this manifestation both troubling and inexplicable, wondering, "Don't the Saudis understand that ISIS threatens them, too?"

It appears -- even now -- that Saudi Arabia's ruling elite is divided. Some applaud that ISIS is fighting Iranian Shiite "fire" with Sunni "fire"; that a new Sunni state is taking shape at the very heart of what they regard as a historical Sunni patrimony; and they are drawn by Da'ish's strict Salafist ideology.

Other Saudis are more fearful, and recall the history of the revolt against Abd-al Aziz by the Wahhabist Ikhwan (Disclaimer: this Ikhwan has nothing to do with the Muslim Brotherhood Ikhwan -- please note, all further references hereafter are to the Wahhabist Ikhwan, and not to the Muslim Brotherhood Ikhwan), but which nearly imploded Wahhabism and the al-Saud in the late 1920s.

Many Saudis are deeply disturbed by the radical doctrines of Da'ish (ISIS) -- and are beginning to question some aspects of Saudi Arabia's direction and discourse.

THE SAUDI DUALITY
Saudi Arabia's internal discord and tensions over ISIS can only be understood by grasping the inherent (and persisting) duality that lies at the core of the Kingdom's doctrinal makeup and its historical origins.

One dominant strand to the Saudi identity pertains directly to Muhammad ibn ʿAbd al-Wahhab (the founder of Wahhabism), and the use to which his radical, exclusionist puritanism was put by Ibn Saud. (The latter was then no more than a minor leader -- amongst many -- of continually sparring and raiding Bedouin tribes in the baking and desperately poor deserts of the Nejd.)

The second strand to this perplexing duality, relates precisely to King Abd-al Aziz's subsequent shift towards statehood in the 1920s: his curbing of Ikhwani violence (in order to have diplomatic standing as a nation-state with Britain and America); his institutionalization of the original Wahhabist impulse -- and the subsequent seizing of the opportunely surging petrodollar spigot in the 1970s, to channel the volatile Ikhwani current away from home towards export -- by diffusing a cultural revolution, rather than violent revolution throughout the Muslim world..........