One reason I didn't stop at this point (although it is important) is because we had known this to be the case anyway. I recently talked about this in a post on Flynt Leverett's latest op-ed in the WP. Here's what I wrote:

Flynt here characterizes Syria's position as "unwillingness, absent a broader strategic understanding with Washington, to stem the flow of people and supplies into Iraq." Yes, "strategic understanding." In other words, the US leaves Iraq immediately, and Syria expands its influence into Iraq. Josh Landis himself wrote that the Syrian regime sees the U.S. presence in the Middle East, specifically in Iraq, as the most serious threat to its vital interests in the region, even more serious than the threat of radical Sunni Islamists. So no amount of "cooperation" will matter. Despite what the Syrians say, it's diametrically opposed to their interests. Furthermore, I'll remind you of what Bashar told Amanpour in the interview on CNN. He made sure to distinguish between insurgents who kill Iraqi civilians, and those who kill US troops. That should give you an idea. The only "deal" the Syrians have in mind, to quote a friend of mine, is one where the U.S. agrees to withdraw, and a "partnership" in which the Syrians see it out the door -- in Lebanon as well as Iraq.