Bribing the Saudis with weapons = key to stability?

America is to give billions of dollars in military aid to Saudi Arabia and other Middle Eastern states. Is it trying to buy friends using weapons as currency? Yep. Will this work out well for anyone, hold the Saudis? Nope.

History repeats itself: Bribing against extremism
This is not the first time the US hopelessly tried to get the Saudis to be a viral beacon of moderacy in a sea of extremism. As this Slate article points out, 26 years ago Reagan tried to bribe the Saudis into joining the peace process... (long quote, I know, but it's worth it):

Twenty-six years later, this rational for selling arms to the Saudis is still valid. Two weeks ago, President George W. Bush announced that the United States will host a regional peace conference in the fall, and clearly the Saudis would be the big "get."
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But luring the Saudis to the peace conference is not the only reason the Bush administration wants to sell the Saudis some of the most sophisticated weaponry on the market. It's not even the main reason. The deal, officially announced by Secretary of State Condoleezza Rice on Monday, "will help bolster forces of moderation and support a broader strategy to counter the negative influences of al-Qaeda, Hizballah, Syria, and Iran," according to her statement.

In short, it is meant to ensure the Saudis' commitment to the "moderate" camp, to help Washington better manage its affairs in Iraq and prepare to block Iranian expansionism in the region. The United States is practically bribing the Saudis to make them more cooperative in Iraq and more confident in light of an emboldened Iran. This is yet another manifestation of an administration that is setting its priorities anew: No more reforming the Middle East—let's focus on managing it in the old, realist way. Using friends, however reluctant, against foe; manipulating regional powers against each other; using whatever regimes are at hand to ease the pressure on the United States.

The problem with the Saudis, though, is that time and again they have proved to be unbribable and unmaneuverable. In fact, it is Riyadh that is manipulating Washington into this questionable deal, using tactics they've been perfecting for decades—never fully committing themselves, always leaving the door open to other alternatives to keep the United States on its toes. If America will not sell them weapons, they might turn to China or Russia. And as for the threat from Iran, they know that the United States knows that leaving the Saudis to their fate is not an option. Not as long as there's no real alternative to the fuel they so generously provide.
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This new deal with the kingdom is no more than another down payment, an attempt to ensure its future cooperation on a number of issues on which the Saudis should have cooperated long ago. ... This is one of many instances in which the Saudis have defied U.S. interests and played the double agent: working with Syria on the fate of Lebanon, orchestrating an agreement between rival Palestinian groups Fatah and Hamas, allowing Saudi businessmen to keep an open channel to al-Qaida.

So why is Saudi Arabia so bad (besides the human rights abuses and support for terrorism, and all that other jazz)?
An influential US envoy to Iraq has even said that Saudi Arabia is a driving force behind the instability in Iraq. Oops... How's that for an example of a moderate and positive Mideast actor with strong ties to America? One has to wonder: In the US-Saudi relationship, who's exploiting who?