Frank nailed it though:

To prop up the Saudi regime.

The citizens of Middle Eastern nations look askance at American promises of freedom and democracy because they aren't dumb. They hear our words and see who we support: our despotic friends in Riyadh, Cairo, and Amman. Until he was foolish enough to invade Kuwait, Saddam himself was one of our friends. Our Arab friends are not friends of liberty.

How convenient for the Princes of Saud, to be able to count on American support without having to even consider the principles that we Americans believe our troops should be used to support.

Regards--
Mary Anne