And there is always the specter of 9/11 hanging over the Saudis. As long as they stay all nicey-nicey with the US, nobody is gonna bring up their involvement. But the instant we decide Saudi Arabia is no longer a critical ally (oh, probably about the time we lift sanctions against Iran's oil), everyone in politics and the media is going to pile on the Saudis. This may become THE surprise issue for the Presidential election, in fact. Everybody is all cozy with the Saudis right now, but once the media machine turns, and decides to shine a bright light on the Saudi involvement in 9/11, we are going to see a lot of political movers get totally run outta town on a rail.
Yeah... I've read way too many books about the middle east and not a one of them has so much as pretended we have anything but selfish self-interest in our relationship with Saudi Arabia. I've seen a bunch of Hubbert Peak curve fits on Saudi oil production that lead me to believe we don't really know... but we do know that our relationship with Saudi Arabia and our dependence on fossil fuels are positively correlated. Open up Iran and things get interesting, especially as there's been a lot of shuffling amongst the oil and defense ministries of Saudi Arabia. Stephen Kinzer went as far as suggesting we ditch Saudi Arabia and Israel and align ourselves with Turkey and Iran. Turkey is making that harder lately... but Iran...