Not everything is going as U.S. officials might have hoped in Iraq.

There has been a series of high-profile attacks, particularly in the west, shaking confidence that Iraq will be able to preserve reduced levels of violence. Baghdad is buddying up to Syria, just as the Obama administration is seeking to isolate the government in Damascus. And Iraqi leaders have insisted that U.S. troops not be granted immunity beyond the end of the year, forcing American military commanders to scramble to redraw a military training plan.

Taken together, the developments hardly seem to add up to the “new beginning” that President Obama had in mind when he announced the end of combat operations just over a year ago.

Still, there’s been at least one positive development lately in Iraq — and, for that, U.S. officials can thank the pro-democracy protesters rising up against President Bashar al-Assad.

One of the significant upsides already from the growing chaos in Syria has been a disruption of the flow of foreign fighters into Iraq to join al-Qaeda’s affiliate there, according to a senior U.S. intelligence official.

“The unrest in Syria has hurt AQI,” the official said, referring to al-Qaeda in Iraq. Syria has been “their conduit, their historical fighter flow. The unrest has gotten in the way of that.”

That’s not to say that al-Qaeda in Iraq is no longer a potent force. In the view of experts, it remains well-organized, and has the ability to stage coordinated strikes.

But the official said Syria under Assad had “enabled” that flow of fighters into Iraq, allowing his border to serve as a major crossroads as part of a deliberate effort to destabilize Iraq and undermine U.S. efforts there.

“Like a thermostat, he could turn it up and down,” the official said. The flow had been shrinking as the unrest expanded and is “even smaller now.”

It’s difficult to know exactly what Assad’s fall would mean for the flow of foreign fighters across the border. But the official said, in the view of U.S. intelligence, there’s little question that Assad will, indeed, fall.

“The end of this story is the end of him,” the official said.