How long has Bush been in office?  Why hasn't he created this good will capital up to now so that now he need only ask and the Saudis and Kuwaitis will gladly open the spigots?  Oh, that's right--good will toward the U.S. by the ME OPEC nations will be created by our threatening Iran.  Sorry, I forgot how reality works.
Actually that might work.  (OK, this is Cheney/Rumsfeld we're talking about, so scratch that).   But this is the idea....

The Saudi and Kuwaiti elite (Sunni) have large Shiite minorities---the Shia of Saudi Arabia all happen to be in oil producing areas---and really don't want Iran pressuring them and causing rebellious ideas among their disadvantaged minorities.

That's why they supported Saddam against Iran in the 1980s---that little invasion of Kuwait wasn't in the plan---and especially why they were against invading Iraq this time.  Because they knew the Arab Shia would take over in Iraq and that would give other people "bad ideas".