I'm going to expand on this post from FP Passport a bit...

On 27 July we learn the Saudi role in the Iraqi civil war was frustrating senior American officials, noting "evidence that Saudi Arabia is providing financial support to opponents of [Iraqi PM] Maliki. The next day we learn of a $20 billion arms deal with Saudi Arabia and other Gulf Arab states. That same day the White House downplayed any mention of tensions, sending Dana Perino out to insist that the US and the Saudis were working closely on security matters. "We have very strong relations on counter-terrorism measures," she said.

With this as a backdrop, former US ambassador to Iraq and sitting US ambassador to the United Nations, Zalmay Khalilzad writes in a NY Times Op-Ed piece:

"Saudi Arabia and a number of other countries are not doing all they can to help us in Iraq," he said.

"At times, some of them are not only not helping, but they are doing things that is undermining the effort to make progress."

The envoy said that some of Iraq's neighbours were not engaging the government or the Shiite-led majority and had no diplomatic representation in Baghdad.

"The level of positive effort that they are making compared to the stakes involved for the region is minimal," he said.

It's doubtful that much of the reported weapon systems mentioned in the deal, "which includes advanced satellite-guided bombs, upgrades to its fighters and new naval vessels," would be much use in the asymmetrical conflict currently being fought in Iraq. That said, they could be 'improvised'. The fate of untold numbers of US servicepersons may in fact be jeopardized by this deal.

Under these circumstances, the US Congress should (and will) add this to its long list of oversight responsibilities.

[UPDATE] Initial reports indicate that Rice and Gates--in an "rare joint show of diplomatic force"--fell flat on their faces.

...Rice pointed to no fresh commitments from the Arabs. A statement issued following a nine-nation meeting promised only "to continue to support Iraq and expand their financial and political support," and restated a general commitment to blocking would-be terrorists and financing that supports them from entering Iraq.

Stay the course.