An independent eastern province would essentially mean the end of Saudi oil wealth although, technically small amounts (less than 5%) are produced outside of the Eastern Province.
Singer also neglected to point out that 14 of the 15 Saudi hijackers got their visas from the American Counsulate in Jeddah (near Mecca), the 15th from Riyhad, the aboriginal homeland to the House of Saud. Not one got a visa in Dahman, in the Eastern province and might have been exposed had they tried, because a good share of the natives there cannot stand the Wahabis.