Stepping Into Iraq" starts by reminding President Bush that in February 2003 the Saudi Foreign Minister had warned him that if the US removed Saddam Hussein by force he would only be solving one problem by creating five more.
Is this common knowledge? Or was it whispered into Junior's ear while they were walking hand in hand in the garden.
As for the Saudi's cutting back on oil sales, I'm not so sure. I had thought that oil wealth is propping up an unpopular king... Stopping oil sales would just give the (even more) radical factions more power and influence. Unless, of course, China can buy the oil formerly slated for the US...
Saudi Arabia's outright support for the Sunnis is possibly one of the few ways things could escalate. This would cause Iran to outright support the Shia, to "prevent the Saudi-backed militia from butchering Shias". I have no idea how the rest of the countries would align. I would fear for Bahrain, which has ties to both Saudi Arabia and Iran, and is the home base of our 5th Fleet.