The first thing to remember is, there are few if any examples in history of a largely materially-served nation suddenly succumbing to a mass theological revolution. The people's of the Gulf region are highly educated, econo.ically prosperous people who largely import their workers and others who are of the 'oppressed class'; but they do this work, like Mexicans and other in America, to escape an even worse situation, and simultaneously support loved ones in their homecountry.

Due to the War on Terror, there has been little incentive for the recent generation to become Islamic fundamentals, and those who remain so also have to weigh recent gains and losses, such as in Syria, or conversely Yemen, and elsewhere, as their numbers and archaic ideals become less embraced while economic opportunities have increased. It is simply less attractive to follow fundamental values—even as we see a sharp decline in religious vigor in the American 'Bible Belt'; it seems horrible and threatening, but is numerically less expansive than ever before. Blame technology or simple human intelligence expanding. Your choice.

There is a mythology of Iranian superintelligence emerging, which credits a terrorist regime with some kind of power born of its fundamentalism which simply planned so far ahead, and was so sophisticated, that it could never actually be toppled. It is here where we bow to various pundits who are magical thinkers, because it is fun.

Every dying regime has a last hurrah. Let's say 30 years (something roughly equivalent to Stalin's death extending to 1989). Khomeini died in 1989, and so it has been roughly as long for the Iranians. If you went back in time (and still) people gave the Soviets much more credit than they deserved. Totalitarianism has a short timeline. Do your own research.

Finally, the idea that dysfunction around the Gulf will bring an end to the West is surely dramatic thinking. If anything, the high functionality of the Gulf region is owed to the West, and partially drew energy away from the West. Explain then how its demise hurts the West rather than drags more investment into it? There would be pains for sure, but the vast amount of geological wealth that lies elsewhere would be soon tapped, and the world would go on. But agreed, it would make a good novel if that didn't happen.