The Bush administration has devised a strategy to declare victory in Iraq even if Saddam Hussein or key lieutenants remain at large and fighting continues in parts of the country, officials said yesterday.

The concept of a "rolling" victory contemplates a time -- not yet determined -- when U.S. forces control significant territory and have eliminated a critical mass of Iraqi resistance. U.S. military commanders would establish a base of operations, perhaps outside Baghdad, and assert that a new era has begun. Even then, tens of thousands of U.S. soldiers would remain to help maintain order and provide humanitarian assistance.

Although President Bush spoke yesterday of accepting "nothing less than complete and final victory," administration officials do not envision a formal Iraqi capitulation in a scene akin to the German surrender to the Allies at Reims that ended World War II in Europe. Rather, they hope to recognize a moment when the military and political balance tilts decisively away from Hussein's Baath Party government.

"The objective is not necessarily to take buildings or occupy areas," said a senior military officer involved in endgame planning. "It's the people. It's getting them to accept the fact that the regime is gone. That's the essence of the thing. It's not going to be a geographic piece."

The timing of declaring victory is important in military and psychological terms, and would be up to the president after a recommendation from military advisers. The administration is set on intimidating Iraqi leaders and seizing power, yet it would risk its credibility by declaring itself in charge while significant resistance remains.

Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff, said yesterday that Baghdad, the Iraqi capital, would not need to be under U.S. control for the administration to establish an interim Iraqi administration. When Baghdad is isolated from the rest of the country, he said, the city is "almost irrelevant."

"Whatever remnants are left would not be in charge of anything except their own defense," Myers told reporters, "and it would be fairly small compared to the rest of the country and what's happening."

Some outside analysts suggest that Baghdad must be in U.S. control before fearful residents of southern Iraq would be convinced that Saddam Hussein and his authoritarian government are gone for good. Until then, some specialists believe, armed opposition could remain strong.

As U.S. forces press in on Baghdad, the Bush administration has been debating how to assert control over the central government and provincial capitals. Planners have been working for months to define victory and, as one said, "figure out what it looks like when we see it."

Many of the administration's senior figures believe President George H.W. Bush declared victory too soon in the 1991 Persian Gulf War, after U.S. forces expelled the Iraqi army from Kuwait but before they toppled Hussein.

One marker explicitly rejected by the White House is the capture or confirmed death of Hussein. The administration does not want its ambitious postwar plans to be held hostage by a search for the Iraqi leader. Opinion polls have suggested that a public perception of success would be reduced if Hussein's whereabouts remain unknown.

During early preparations for war, one official said, some U.S. thinkers "operated on the assumption that it was going to be a relatively clean break, that the end of the regime would be clear for all to see. That may not be the case. I think we're seeing a rolling end."

The concept of a rolling end is a mirror of the war's rolling start, in which U.S. troops began attacking without the full invasion force in place. A rolling end also represents a concession that the endgame may not be tidy.

"It's going to be a fairly nebulous situation," predicted one civilian official, who outlined how things could develop. Much would depend on an assessment by Gen. Tommy R. Franks, the senior military commander in the region, that a certain part of Iraq was free of danger and that important elements of Iraq's leadership had been neutralized or eliminated.

He would make a recommendation to Bush that his military headquarters be moved from Doha, Qatar. When resistance has been cleared from the area -- a small town would be more likely than a hard-to-police big city -- Franks and his reconstruction chief, retired Lt. Gen. Jay M. Garner, would move in, the official said.

From the cleared area, U.S. control would expand outward as security improved.

"Victory means more than knocking down what existed," said Douglas J. Feith, the Pentagon's undersecretary for policy. "It means putting some substitute in place that will help the Iraqis get what they need and be in a position to begin to govern themselves."

Hussein's health and whereabouts will play an important role in the endgame, according to analysts and U.S. officials. Intelligence analysts said evidence increasingly supports the theory that the Iraqi leader is injured or dead, although nothing is yet definitive.

"If we find Saddam's body, then I think the place will fall apart. You will see people embracing the fact that he's gone," said Kenneth M. Pollack, an Iraq specialist at the Brookings Institution's Saban Center for Middle East Policy. "The bigger problem is if he's in charge in Baghdad. It gives people the thought that the Americans might not have the guts to assault" Iraqi cities.

A number of outside analysts said a truer definition of victory will require U.S. control of Baghdad.

"Until you take over Baghdad and clean out most of the Saddam elements, you haven't finished the job," said James Bodner, a high-level Clinton administration defense official. A strong start on reconstruction, he said, requires Iraqis being "sufficiently lacking in fear of security agents to cooperate with U.S. authorities."

Looking for parallels, a number of administration officials point to the war in Afghanistan. Taliban leaders never formally surrendered but simply vanished. U.S. forces declared victory once the principal cities of Kabul and Kandahar had fallen. An interim Afghan authority was created later.

The world has recognized the Afghan government of Hamid Karzai, although it does not control much of the country outside Kabul. Remnants of the Taliban government and the al Qaeda terrorist network continue to menace U.S. forces, particularly in eastern provinces bordering Pakistan. More than 17 months since the war began, U.S. officials have yet to declare combat operations over.

Clinton administration foreign policy adviser James B. Steinberg believes it would be risky to declare victory too early, particularly given Iraq's historic divisions and difficulties. He said an initial stage of victory would come when the Iraqi leadership is gone, organized military opposition has ended and U.S. forces "significant control over the major power centers."

"There isn't going to be a single moment when we can say, 'Okay, good. This is done,' " said Steinberg, director of foreign policy studies at the Brookings Institution. "Because even if we got a formal surrender, there would still be a lot of challenges going forward. So it's right to be modest about saying that you've, quote, won, just because certain phases of the battle are over."

Staff writer Mike Allen contributed to this report.