King Salman bin Abdul-Aziz Al Saud’s decision to remove Crown Prince Mohammed bin Nayef and promote his favorite son, Defense Minister Mohammed bin Salman, has been long anticipated. It raises profound questions about the future stability of America’s oldest ally in the Middle East.

The king has now twice removed the sitting crown prince, a heretofore unprecedented move in the kingdom. Two years ago, Salman deposed his half-brother Prince Muqrin with no explanation and promoted Mohammed bin Nayef. The latest move puts Mohammed bin Salman, 31, next in line for the throne.

For over half a century, the line of succession in the kingdom moved laterally among the sons of the founder of the modern kingdom, King Abdul-Aziz. This process produced stable, legitimate and predictable outcomes, but its end was inevitable. By removing Muqrin, King Salman accelerated the moment of truth. Now he has skipped a generation in the succession process and gone to the grandsons of Ibn Saud. The royal court has announced that a majority (31 of 34) of the living descendants of Ibn Saud (the members of the Allegiance Council) approved the change.

Mohammed bin Nayef has been the powerful interior minister for a decade, overseeing a million-man bureaucracy that ruthlessly fought both terrorism and dissent. The “deep state” was his power base but Mohammed bin Nayef has seen his role steadily diminished by the king. Salman revoked the ministry’s power to prosecute just days ago. Mohammed bin Nayef’s health has also been a question since he survived an assassination attempt by al-Qaeda in 2009. He was so depressed that he spent over a month sulking in Algeria a year ago, neglecting his duties.

Read the full article in Al-Monitor.