"Muhammad ibn Saud and Muhammad ibn Abd al-Wahhab had concluded a formal agreement in 1744: according to one source, Muhammad ibn Saud had declared when they first met,
"This oasis is yours, do not fear your enemies. By the name of God, if all Nejd was summoned to throw you out, we will never agree to expel you." Muhammad ibn Abd al-Wahhab replied, "You are the settlement's chief and wise man. I want you to grant me an oath that you will struggle with me against the unbelievers. In return you will be imam, leader of the Muslim community and I will be leader in religious matters."
Ibn Saud accordingly gave his oath. The descendants of Muhammad ibn Saud, the Al Saud, continued to be the political leaders of the Saudi state in central Arabia through the 19th and into the 20th centuries, and eventually created the modern Kingdom of Saudi Arabia in 1932. The descendants of Ibn Abd al-Wahhab, on the other hand, have historically led the ulema, the body of Islamic religious leaders and scholars, and dominated the Saudi state's clerical institutions.
The agreement between Ibn Abd al-Wahhab and Muhammad ibn Saud of 1744 became a "mutual support pact" and power-sharing arrangement between the Al Saud and the Al ash-Sheikh, which has remained in place for nearly 300 years. The pact between the two families, which continues to this day, is based on the Al Saud maintaining the Al ash-Sheikh's authority in religious matters and upholding and propagating the Wahhabi doctrine. In return, the Al ash-Sheikh support the Al Saud's political authority  thereby using its religious-moral authority to legitimize the royal family's rule. In fact, each legitimizes the other.This alliance formed in the 18th century provided the ideological impetus to Saudi expansion and remains the basis of Saudi Arabian dynastic rule today.  wiki on Wahhabism
General (ret) Jack Keane Fox News' "Senior Strategic Analyst" said on the air yesterday that the Saudi government "needs to distance itself from the Wahhabis." this statement displayed a breathtaking lack of knowledge and understanding of Saudi history and actual religiopolitics.
A few thoughts:
1. Islam as an idea system does not recognize the legitimacy of secular rule. Most majority Islamic countries have secular government of some sort. These governments are the result of exposure to Western political thought through colonial experiences or prolonged exposure to such thought by education in Europe or America. That admixture of ideas does not replace the ideal of theocracy in Salafi (purist) Islamic thought which continues to hold secular rule to be impious.
2. Islamic culture does not normally legitimize the concept of kingship. (malikiya) or rule by a sultan or shah (Iran). Islam as such seeks a worldwide Islamic community ruled by scholars and judges of the Islamic law (sharia). A sultan is someone who merely holds actual power to control land, population and territory. The term does not denote legitimacy from the Islamic point of view. Islamic history is dotted with individuals with title of secular rule who claimed Islamic legitimacy because they were also head of some dissident Islamic sect. An example would be the Sultan of Oman who protects the dissident and from the Sunni point of view heretical and apostate Ibadhi sect. The Jordanian and Moroccan kings are generally accepted as legitimate rulers only because they are believed to be Alids, descendants of the Prophet Muhammad, and endowed with a special barakat (grace) from God. The Ottoman Sultan derived his supposed legitimacy from being both sultan and caliph (commanders of the faithful) The Ottomans created this dual status in the 16th Century CE precisely because they sought a plausible claim of Islamic legitimacy as head of the 'umma. The lack of a plausible claim to Islamic legitimacy was IMO the major weakness of the Pahlavi dynasty in Iran This weakness made possible effective resistance to them that eventually resulted in the rule of the mullahs and wilayet al faqih (rule of the scholars).
3. The Al as-Saud (the Saudi royal family) have none of that. As stated in the text quoted above, their claim to Islamic legitimacy derives entirely from their 300 year old relationship with the Wahhabi cult. They and the Wahhabi 'ulema are locked in an embrace that has been until now utterly unbreakable because the general internal consent to their "kingship" is based altogether on the Al as-Saud's role as protectors of what has been seen among the Wahhabi masses as the only true form of Islam. They and the Al as-Sheikh family are a kind of moiety, a duopoly related by function and often marriage in the control of what became Saudi Arabia in the early 20th Century.
4. Saudi Arabia is a medieval state adorned with modern infrastructure. Their society never experienced anything like the Renaissance that brought Europe out of the medieval mindset. The Saudi rulers think the ideas of statehood that emerged following the Treaty of Westphalia to be a joke that the Europeans and Americans claim to believe in. They see the rest of the world, including non-Wahhabi Muslims as "the other," enemies to be thwarted, tricked ad exploited . The notion that they will be shamed by what Mister Bone Saw did is ludicrous.
5. IMO Trump, Pompeo et al are seeking a way to preserve the relationship of the US with this demoniacal relic of the medieval past. My WAG on this is that MBS and company will construct a suitable fall guy group from whom confessions will be extracted claiming them to be "rogues" and then the "conspirators" will be executed, probably in public.
6. The Al as-Saud will then wait to see if the West is mollified. IMO they will not accept any form of punishment for what they see as just retribution visited upon Khashoggi. If threatened they will try to retaliate.
For those who would actually wish to understand all this I would recommend "The Social Structure of Islam" by Reuben Levy and "The Venture of Islam" 4 vols. by Marshall Hodgson. Both these works are concerned with the high culture of Islam.