Some top U.S. military officers are questioning whether the practice of keeping U.S. troops highly visible in Iraq is doing more harm than good, challenging a key tenet of the Army's approach to occupying the country.

Advocates of the new approach say U.S. troops would be more effective if they were kept out of view of the Iraqi public, and even removed to remote desert bases, appearing only when needed to conduct operations beyond the capacity of Iraqi security forces.

For most of the Iraq occupation, the U.S. military has assumed -- based on lessons drawn from peacekeeping missions in Bosnia and Kosovo -- that maintaining "presence" through extensive patrols, large-scale raids and other highly visible operations would increase stability. Now, however, some officers are saying that such operations are doing more to inflame anti-American feelings among Iraqis than to secure the streets, and the resulting debate may shape the military's future structure and tactics in Iraq.

"Sometimes the best way is to be less present, and to be focused in your presence and successful in what you do," Gen. Peter J. Schoomaker, the Army chief of staff, said in little-noticed comments made last week during the final moments of a hearing of the House Armed Services Committee. "And by exposing more and more of your formation to this kind of [guerrilla] warfare may not be the smartest thing to do. And we're looking and working very hard to do that through the commanders over there."

The view that high-profile U.S. military operations may be counterproductive departs from the basic U.S. military approach in Iraq over the past year. As one 1st Armored Division soldier put it in summarizing his unit's operations in Baghdad for the past 14 months, "We were everywhere all the time day and night 24-7 for a year -- I mean everywhere. You could not go anywhere in Baghdad without seeing a 1st AD patrol or convoy or soldiers on some point."

The changing view on presence also presents a new challenge to critics of the Bush administration's Iraq policy, such as Sen. John McCain (R-Ariz.) and Rep. John P. Murtha (D-Pa.), who have called for boosting the number of U.S. troops there. In May, Murtha, a decorated Marine veteran of the Vietnam War, said the administration should either increase its troop strength in Iraq or withdraw. Until now, U.S. commanders have generally agreed with the need for troops, postponing plans for cuts this summer and instead maintaining a level of about 145,000 troops.

Somewhat belatedly, the revised approach to presence also provides new ammunition for Defense Secretary Donald H. Rumsfeld's approach to Iraq, which, beginning with the government- toppling campaign in the spring of 2003, favored maneuverability and speed over sheer bulk and big troop numbers.

Asked Wednesday about the continuing debate over troop levels, Rumsfeld said, "There's no magical number. There's no formula for this." But he went on to say at a Pentagon news conference that the Soviet Union had a large troop presence in Afghanistan during its war there in the 1980s, while the U.S. military had just "a few handfuls" in its own offensive there in the fall of 2001. "The Soviets lost and we won," he pointedly noted.

The new argument against "presence" as a military goal was put most strongly by Keith W. Mines, a former Special Forces officer who served a tour last year as the U.S. occupation authority's representative for Al Anbar Province in western Iraq. "The presence of foreign security forces is provoking the very instability that must diminish in order for the process to work," Mines, who is now a State Department diplomat, wrote in an essay published by the Foreign Policy Research Institute, a pro-defense think tank that tends to espouse mainstream Republican views. "Coalition forces are not only not stopping most of the violence, they are the active force which is provoking it."

In a follow-up internal cable sent last month on the State Department's formal "dissent channel," Mines also argued for a phased withdrawal of U.S. troops, with a reduction from dozens of bases now to just seven in January, followed by a complete pullout in the spring.

Some Army officers, especially those who specialize in civil affairs, the art of military relations with the local population, say they agree with Mines's thesis.

"I certainly think Mines is on to something," said Army Maj. Christopher Varhola, a reservist who served in Iraq earlier this year. Varhola, who is writing an academic study titled "The American Military in Iraq: Are We Our Own Worst Enemy?," said he came away from Iraq believing that U.S. military operations "have alienated parts of the Iraqi population, and continue to do so."

Not everyone in the Army supports that view. Capt. Oscar Estrada, an Army Reserve civil affairs specialist, found that out the hard way when he published an article in The Washington Post last month detailing his concerns that even feel-good missions, such as fixing water plants, are harmful if soldiers shoot at Iraqis on the way to and from the task. In response, he was transferred to a post near the Iranian border, resulting in the loss of a home leave during which he planned to get married. According to the Army Times newspaper, he also was reprimanded by his brigade commander, Col. Dana J.H. Pittard, who told him he was "aiding the enemy."

Likewise, Brig. Gen. Mark P. Hertling, deputy commander of the 1st Armored Division, which occupied Baghdad for most of the past year, argued that Mines's views are "interesting, but also somewhat slanted, geared toward what he saw in Al Anbar (versus the entire nation, which has different challenges in each area) and uninformed."

At the same time, Hertling said the Army already has taken many of the steps Mines advocates. He said the 1st Armored Division has long conducted the kind of focused operations Mines says are necessary. "If our units didn't have a specific mission, the soldiers didn't go out," he said. In addition, he said, the division steadily reduced its number of outposts in the capital from 60 in spring 2003 to eight early this summer.

Maj. Gen. Charles Swannack Jr., who commanded the 82nd Airborne Division in western Iraq for much of the past year, said he generally endorses the idea of putting Iraqi security forces at the fore while U.S. troops move to the background. The problem, he said in a talk in Washington last month, was that the U.S. aid program has been too sluggish to put that theory into practice. "I never got to the point where we had the equipment to do that," said Swannack, who worked with Mines in Al Anbar. "I couldn't get the flak vests, communications and vehicles to do that."

Even so, the new view is clearly gathering steam. Defense analyst Michael Vickers, who has long advocated sharply cutting U.S. troop levels in Iraq, said that some Pentagon insiders agree with him that it would be possible to have the same military effect in Iraq with half the number of U.S. troops. "They're moving in the right direction," he said, by making U.S. operations less obtrusive. But he said the Bush administration will not sharply reduce troop numbers for fear of looking as if it is cutting and running from Iraq.

The alternative approach is finding support in Congress. Rep. Jim Marshall (D-Ga.) said he learned as a reconnaissance platoon sergeant fighting in Vietnam that "just being out there poking around . . . is strategically counterproductive."

Reducing the U.S. profile as appears to be already happening in some parts of the country almost certainly will reduce U.S. casualties -- which could be significant in Iraq and the United States as the presidential election approaches. However, the tactical shift also is likely to place new burdens on Iraqi security forces, which in several instances proved not up to the job in the last major spike in violence in April.

Marshall, who has made two trips to Iraq in the past year, said the issue for U.S. commanders will be finding a way to reduce their presence without simply surrendering turf to insurgents. "The real dilemma is when you leave a vacuum," he said, "because that lawless environment will be filled by hard-liners, so there's a balance that needs to be struck."

Gen. Peter J. Schoomaker, the Army chief of staff, told a House hearing last week that "exposing more and more of your formation to this kind of [guerrilla] warfare may not be the smartest thing to do."