It is no accident that the majority of the 9-11 terrorists were born in Saudi Arabia but were Yemeni Citizens. They were the sons and grandsons of laborers brought into Saudi Arabia to do the stoop labor and service jobs that the Saudi Citizens would not. About 20% of Saudi Arabia's population is in this category.
Can you imagine anything more frustrating than living and laboring in the shadow of opulence knowing that you are prevented from even aspiring to a higher station in life, that you cannot ever be a citizen in the land of your birth?
This pool of frustrated people is trained in Saudi sponsored schools that their plight, and that of the Muslim World in general, is not the fault of their Saudi Muslim Brothers and benefactors but the West and the United States and Israel in General. Graduation for those that learned their lessons best is to the Terrorist Training Camps (all outside Saudi Arabia) and out into the world to take their revenge.
It is my belief that Saudi Arabia is the "Elephant in the Room" and will have to be dealt with sooner rather later.