A former senior official said that he did not expect political pressure to affect Bush's decisions on Iraq this year but that the 2008 presidential election could be a different story.

"There is deep concern in the White House that 2008 will be a referendum on Iraq," he said. "I don't think the president will be affected by the congressional elections. But in 2007, at some point, does he say, 'I'm going to do what's right, no matter what the political consequences?' Or does he say, 'We gave the Iraqis every chance; we can't want a successful Iraq more than the Iraqis want it?'

"Leaving Iraq in its current state would be a very serious strategic setback for us," he said. "It would be a defeat. We can dress it up. We can try to recover from it. But it's a defeat."

"The Sunnis already see us as having chosen sides," said Steven Biddle, a former professor at the U.S. Army War College who is at the private Council on Foreign Relations.

Biddle has argued that by building new Iraqi security forces dominated by Shiites and Kurds, the United States in effect has armed and trained two of the sides in the Iraqi conflict. The Sunnis, he wrote in a recent article, "perceive the 'national' army and police force as a Shiite-Kurdish militia on steroids."

"I think we're in a civil war now. We've been in a civil war for more than a year. It's just a civil war that's being fought at low intensity," he said in an interview.

Instead of trying to build Iraqi security forces quickly, Biddle argues, the United States should slow down its training program, slow its own military withdrawal, and concentrate on strengthening political leaders — especially among the Sunnis — who can make compromises.

But Biddle acknowledges that there is no political support in the United States for a longer or larger troop deployment.

"If we had the troops, I'd increase the troops," he said. "But we don't have the troops."