There are two areas where Saudi Arabia will keenly feel Nayef's loss. First, his relationship with the kingdom's powerful religious hierarchy was critical: His ties to the Committee for the Promotion of Virtue and the Prevention of Vice, more commonly known as the haia, allowed him to monitor the behavior of Saudi Arabia's religious police force, the mutawa, who serve under the command structures of his Interior Ministry. His influence was instrumental in reforming and even gently admonishing the mutawa when they were perceived to have gone too far in their often zealous enforcement of religious law, as occurred in June 2011 when Nayef politely "suggested" that the mutawa treat Saudi citizens with more respect.
Nayef was also adept at keeping the clerical establishment on its toes, primarily through a mixture of coercion and redistribution of land grants. This granted him great sway over the behavior of the kingdom's garrulous religious sheikhs, and his death leaves space for a potentially more assertive clerical establishment in the coming months. Although the king has waded into this topic -- as evidenced by his sacking last month of vice minister of justice and royal advisor Sheikh Abdelmohsen al-Obeikan -- Nayef's loss will most certainly affect how the religious establishment projects its power in the future.
Saudi Arabia's Yemen policy may also suffer from the lack of a powerful figure at the helm. Both former crown princes, Sultan and Nayef, held considerable sway when it came to relations with the kingdom's southern neighbor. Both men funded large and extensive patronage networks in the country, balancing the need for a strong central government capable of destroying al Qaeda with the need to prevent former President Ali Abdullah Saleh from becoming too big for his britches. The result was a curious mix of funding and interference that formed a cobweb of interests and associations, deeply linking Saudi Arabia to Yemen's fate. When Sultan died, Nayef assumed much of this portfolio, but was unable to replicate the depth of his brother's connections. Now that Nayef is himself dead, there is no strong man in Saudi Arabia to oversee Yemen's fragile post-Saleh transition, and it is unknown whether Nayef's former subordinates are up to the job of maintaining Saudi influence in Yemen.
No discussion of Nayef's death, of course, would be complete without a mention of succession. The next choice for crown prince has already been named: Defense Minister Prince Salman bin Abdulaziz, Nayef's full brother. All those who know the man speak highly of his work ethic, his attention to detail, and the impact he has made since becoming defense minister in November 2011.
What is more concerning is who succeeds Salman, and that question has no easy answer. It is possible that Salman could become king at any moment given Abdullah's age and health concerns, leading to an urgent need for yet another crown prince. At this moment, a shift to the next generation is highly unlikely, for no grandson of Abdulaziz is yet ready to assume the mantle of crown prince. While there are some very strong candidates -- the strongest of whom is arguably Mohammed bin Nayef -- more time is needed for these princes to establish themselves in a strong enough position with all branches of the family. Age is a crucial factor in determining seniority in the House of Saud, and while Mohammed or Saudi Arabian National Guard commander Miteb bin Abdullah are clearly capable, their relative "youth" is currently a major hindrance. The exception here is Mecca Governor Khalid al-Faisal, who at 71 years old possesses both age and gravitas -- but at the present time there is little to suggest he is widely favored.
Excluding sons who do not seek the throne, this leaves four potential candidates from Ibn Saud's surviving sons: Interior Minister Prince Ahmad, Riyadh Governor Prince Sattam, Prince Muqrin, and potentially Baya Council senior member Prince Hazloul -- and there is no clear indication of which might be viewed favourably at the current time. Muqrin in particular is at a disadvantage given his Yemeni mother, but Ahmad and Sattam, although well known among the Saudi population, are not true powerhouses in the Saudi decision-making apparatus and certainly would not win outright support from the Baya Council in its future deliberations over a crown prince. Hazloul is something of an unknown quantity, though kingdom watchers would do well to see how he positions himself in family politics in the coming months.
While there is no clear line of sight as to who might take over as crown prince if and when Salman vacates the position, one thing is for sure: Whoever is chosen will receive the family's automatic backing. Such is the way with the princes of the House of Saud: They will accept these decisions for the good of the ruling collective, as they have always done. Nayef's death injects some urgency into the process, but it's the desire for stability that is the true king of Saudi Arabia.