WASHINGTON (By Peter Baker. Washington Post ) Thursday, December 21, 2006 —

At an end-of-the-year news conference, Bush said he agrees with generals "that there's got to be a specific mission that can be accomplished" before he decides to dispatch an additional 15,000 to 30,000 troops to the war zone. But he declined to repeat his usual formulation that he will heed his commanders on the ground when it comes to troop levels.

Bush sought to use the 52-minute session, held in the ornate Indian Treaty Room in a building adjacent to the White House, to sum up what he called "a difficult year for our troops and the Iraqi people" and reassure the American public that "we enter this new year clear-eyed about the challenges in Iraq." Asked about his comment to The Washington Post this week that the United States is neither winning nor losing the war, Bush pivoted forward. "Victory in Iraq is achievable," he said.

The tension between the White House and the Joint Chiefs of Staff over the proposed troop increase has come to dominate the administration's post-election search for a new strategy in Iraq. The uniformed leadership has opposed sending additional forces without a clear mission, seeing the idea as ill-formed and driven by a desire in the White House to do something different even without a defined purpose.

Abizaid's announcement amid that debate could shift the dynamics. His retirement in March had been expected, given that he has led the U.S. Central Command longer than any predecessor and had already extended his assignment at the request of then-Defense Secretary Donald H. Rumsfeld. But Abizaid has been a forceful voice of doubt about the utility of a surge, and his imminent departure could make it easier for the White House to shift direction.

During a news conference in Baghdad alongside newly installed Defense Secretary Robert M. Gates, Abizaid declined to discuss troop levels except to say "all options are on the table," and he characterized his retirement as appropriate. "No decision that anybody makes in a position like this is ever totally their decision," he said, "but I think the time is right, and it has nothing to do with dissatisfaction."

The internal struggle over troop levels in Iraq has exposed a schism between civilian and military leadership 45 months into a war that, at the moment, has no end in sight. Testifying before a Senate committee Nov. 15, Abizaid bluntly rejected the surge option, saying: "I do not believe that more American troops right now is the solution to the problem. I believe that the troop levels need to stay where they are." Other generals have been equally resistant in public and private comments.

Bush has traditionally paid public deference to the generals, saying any decisions on moving U.S. forces in the region would depend on their views. At a Chicago news conference in July, for instance, Bush said he would yield to Gen. George W. Casey Jr., the Iraq commander.

"General Casey will make the decisions as to how many troops we have there," Bush said, adding: "He'll decide how best to achieve victory and the troop levels necessary to do so. I've spent a lot of time talking to him about troop levels. And I've told him this: I said, 'You decide, General.' "

By yesterday, however, Bush indicated that he will not necessarily let military leaders decide, ducking a question about whether he would overrule them. "The opinion of my commanders is very important," he said. "They are bright, capable, smart people whose opinion matters to me a lot." He added: "I agree with them that there's got to be a specific mission that can be accomplished with the addition of more troops before I agree on that strategy."

A senior aide said later that Bush would not let the military decide the matter. "He's never left the decision to commanders," said the aide, who spoke on the condition of anonymity so Bush's comments would be the only ones on the record. "He is the commander in chief. But he has said he will listen to those commanders when making these decisions. That hasn't changed."

As he consults with the Joint Chiefs on troop levels in Iraq, Bush has tried to address their broader concern about the overstretched armed forces. He told The Post on Tuesday that he plans to expand the size of the Army and Marines and repeated that intention yesterday while denying that his decision amounted to a repudiation of Rumsfeld's efforts to build a lighter, more agile military.

On his first tour of Iraq yesterday, Gates said "we're just beginning that process" of figuring out how much to expand ground forces overall. But he cautioned that the long-term project was not related to the immediate question of what to do in Iraq. "An increase in the size of the Army today really won't show up for some period of time," Gates said.

Sen. Bill Nelson (D-Fla.), wrapping up his own visit to Iraq, said a surge might be helpful in Anbar, the western province that has been a haven for al-Qaeda. "But in Baghdad," he told reporters from Kuwait, "it's not going to help unless the Iraqis decide that they're going to get their act together and stop sectarian violence."

Incoming Senate Majority Leader Harry M. Reid (D-Nev.) said Bush's latest remarks indicate that he has not come to grips with the need for urgent change in Iraq. "The president seems lost within his own rhetoric," Reid said in a statement. "He is grasping for a victory his current policies have put out of reach and leaving our troops stuck policing a civil war."

Bush argued that failure in Iraq would be an even worse result and expressed confidence that many Americans "understand the consequences of retreat." As he prepared to begin his holiday break at Camp David and his ranch in Crawford, Tex., he ruminated in response to questions on the difficulty of wartime leadership but said he harbors no doubts about his decision to invade Iraq in 2003. "The most painful aspect of the presidency," he said, "is the fact that I know my decisions have caused young men and women to lose their lives."

An antiwar group reacted angrily to the comments.

"I know that my son's life was wasted, thrown away like it was nothing," Michelle Deford, whose son, Army Sgt. David Johnson, was killed in Iraq in 2004, said in a statement released by Gold Star Families Speak Out. "What we need to do is bring the rest of our sons and daughters home now."