Bait and switch
When wealthy autocrats wish to distract their subjects from the fact that they, the subjects, are not sharing in the wealth and power of the country, the answer has been to find or invent an enemy in order to focus attention on this "other" enemy rather than on the autocrats.
The Saudis remain on their tottering throne because of the deal they made with the Wahhabbist clergy. It's turning around to bite them now because they are under pressure from the "enemy", us, who also happen to be their chief prop. No one said that autocrats had to be smart.
Marx got some things right. Under the right conditions, religion really is the opiate of the people.
If the people are doing well, they have less incentive to blow up themselves and others.