WASHINGTON — The harder President Bush has pushed to win in Iraq, the closer he has come to losing.

The question no longer is whether the U.S. military can fully stabilize Iraq. It cannot.

That was a possibility four years ago. Before the insurgency took hold. Now only the Iraqis can save Iraq.

The Bush administration has made no secret of the fact that the U.S. troop buildup in Baghdad is just buying time for the Iraqis to sort out their differences, create a government of national unity and show they can defend themselves.

So it is not whether the U.S. can win the war. It is whether the Iraqis can, which is in great doubt.

In a speech Thursday, Bush cited Israel as a model for defining success in Iraq: a functioning democracy that nonetheless absorbs terrorist attacks.

Among the questions central to the debate in Washington over winding up the conflict without widening it are:

• How much worse might things get if U.S. troops left and the sectarian killing escalated?

• Would Turkey, Iran or other neighboring states intervene militarily?

• Would the al-Qaida terrorist organization inside Iraq secure a lasting haven from which it could launch attacks across the region?

While there is no clear way out, there remains a reasonable basis for hope of escaping a collapse of the war effort.

It still is possible that the troop buildup will reduce sectarian violence in Baghdad enough to create the maneuvering room that Iraqi leaders need to make critical political progress.

But time seems to be working against Bush — in the political arena and on the battlefield.

The longer U.S. forces fight, the more creative and deadly the insurgents become, the further U.S. public support erodes and the more remote seem the chances that when troops finally leave, the outcome will look like victory.

The risk is that it may resemble defeat.