General David Petraeus

The last of the additional U.S. troops President Bush ordered to Iraq won't even be there until the middle of next month, but already reporters are asking what will happen after the new Iraq commander, General David Petraeus, makes his first progress report in September.

At a news conference Thursday, Secretary Gates would not speculate on what decisions might be made at that time, but he counseled patience. "We can't turn it around overnight. And we just have to have the patience to let this play out and see if General Petraeus' strategy is going to produce positive results," he said.

But for some experts, patience until September isn't nearly enough. "I don't think we'll realistically have the necessary trend lines developing until spring of next year," said retired U.S. Army Colonel Paul Hughes, who is now an analyst at the U.S. Institute for Peace in Washington. "I think we need to really suppress our desire to have good news early because good news early in a war usually is based on false hope. Once the troops are on the ground, it's going to take probably eight to 12 months before they really begin to see the results where they can say, 'OK, we've got a trend line here that we can trust,'" he said.

But it may be difficult for some Bush administration officials and members of congress to wait that long. The president himself indicated he is focused on the September report during his own news conference on Thursday. "David Petraeus felt like it was important to tell the White House and tell the congress that he would come back with an assessment in September. It's his decision to give the assessment. And I respect him and I support him," he said.

The president also said the general's assessment is more important than anything members of congress might say. And Secretary Gates said the Petraeus report will be combined with the views of other senior generals and civilian officials to create an "overall evaluation" for the president to use in September as he decides whether to continue with the new strategy or make further changes.

For international security analyst Michael O'Hanlon at the Brookings Institution, the general's report will have to show progress in order to justify continuing the current level of U.S. military commitment in Iraq.

"All the trend lines should be in the right direction, or at least the overwhelming majority of them. The violence should be down substantially. There should be progress toward political reconciliation in Iraq. The economy, presumably, may be starting to show more life than it is now. You should be able to see that this thing is working, even if there is still a lot more work to do," he said.

O'Hanlon says it might not be possible to make that kind of progress in Iraq, especially by September, regardless of what strategy is used. But he says a lack of substantial progress by September will likely result in strong action by the Congress. "If the surge fails to make major progress by September, I think the congress could force an outright end to the war by 2008, whereas if the surge is working we could be modestly below the 160,000 troop number by 2008, but we would expect to stay well over 100-thousand throughout the remainder of Mr. Bush's presidency. So it's a fairly stark contrast. Either way you might see a reduction, but one reduction could be gradual and modest, the other reduction could be almost complete," he said.

And O'Hanlon says if there is not significant progress by September, the congress will be in a stronger position to insist on curtailing U.S. involvement in Iraq than it was this week, when it was forced to compromise with the president on war funding.

Retired Colonel Paul Hughes says forcing a quick withdrawal of most U.S. troops would be a mistake. "I don't think you'll see a substantial withdrawal of American forces for probably two or three years. This is a very rough region over there. It's a very tough world. And Americans can't sit within their borders and think that, 'Gee, we'd like to have our troops home right away because they're our troops.' Well, we're the superpower in the world and we have obligations that we have to fulfill," he said.

That argument fits with President Bush's view that a premature U.S. withdrawal from Iraq would have dangerous consequences for the Middle East and for the United States and its allies. But it may be difficult to get much support for that view in the congress, or in U.S. public opinion polls, if General Petraeus does not report strong progress in the relatively short time between now and September.