Air Force Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff, tried to silence a growing chorus of critics of the Iraq war plan yesterday, saying the second-guessing by active and retired military officers was "bogus" and harmful to troops engaged in combat.

In their most extensive comments to date, Myers and Defense Secretary Donald H. Rumsfeld strongly defended the war plan as more than adequate for the military campaign. Twelve days into the war, Rumsfeld said, the fighting strength of Iraqi President Saddam Hussein's elite Republican Guards has been badly damaged by air and ground attacks; allied forces are moving on Baghdad from the south, north and west; and "the circle is closing."

Hours after Rumsfeld spoke, the U.S. Central Command announced in Qatar that U.S. forces had rescued an American prisoner of war, while U.S. Army forces clashed with Republican Guard units near Karbala, about 50 miles southeast of Baghdad, in their first major ground battle against Iraq's best-trained force.

But nagging questions over the Iraq battle plan continue to divert the attention of the Pentagon leadership. For nearly a week, Rumsfeld and Myers have been bedeviled by retired Army generals, such as Barry R. McCaffrey, and some current officers who have said Rumsfeld's desire to showcase his vision of a technologically advanced, fleet ground force had delayed deployments of heavily armed troops and pushed the military into fielding an army that has proven to be too lean and overextended.

In a news conference at the Pentagon, Rumsfeld was unapologetic, at once defending the war strategy and saying it was created by the commander of forces in Iraq, Army Gen. Tommy R. Franks. "The plan is open and it's broad and it's flexible and it allows for all of those kinds of adjustments," Rumsfeld said.

It was Myers, a usually taciturn, unflappable Kansan who broke character with an animated defense of the plan and an attack on its critics. The criticism is "bogus," Myers said, uttered by people who "either weren't there, don't know, or they're working another agenda."

Moreover, Myers added, "it is not helpful to have those kind of comments come out when we've got troops in combat, because, first of all, they're false; they're absolutely wrong; they bear no resemblance to the truth; and it's just harmful to our troops that are out there fighting very bravely, very courageously."

White House spokesman Ari Fleischer weighed in as well, telling reporters President Bush "has faith in the plan, has set the plan; the plan is working."

Over the past several days, as first reported by The Washington Post, senior U.S. military commanders in Iraq as well as retired officers at home have questioned some of the Pentagon's assumptions behind the war plan. They have said the conflict likely will last longer than expected and will require a larger force than is on hand in Iraq and Kuwait.

The critics have said that once it became clear Turkey would not allow the powerful 4th Infantry Division to open a northern front from its territory, the Bush administration should have delayed an attack until the division had reached Kuwait to roll in from the south. The division is not slated to reach Iraq until the middle of the month. And, the critics have said, Rumsfeld's personal meddling delayed the deployment of some units -- such as the Second Armored Cavalry Regiment, which is now heading to the Middle East -- and prevented the dispatching of other units, such as the Third Armored Cavalry Regiment, which has not left its bases in the United States and Germany.

The public battle over the war plan can be seen as only the latest -- and most dramatic -- skirmish in a war between Rumsfeld and the Army. Since Rumsfeld came to the Pentagon, current and retired Army leaders have seen him as a threat, as he pushed his vision of a fleet-footed, high-technology force dominated by Special Forces, small, rapid-deployment units and air power wielding precision-guided bombs and missiles. Army leaders have seen that vision as a challenge to their heavy divisions built around hundreds of slow-deploying tanks, helicopters and artillery systems.

Flare-ups include Rumsfeld's selection of a successor to Army Chief of Staff Gen. Eric K. Shinseki more than a year before Shinseki's planned retirement, the secretary's abrupt cancellation of the Army's Crusader self-propelled artillery gun and, weeks ago, Deputy Defense Secretary Paul D. Wolfowitz's public dispute with Shinseki over the size of a force needed to occupy Iraq once hostilities cease.

Indeed, the Marine Corps, the nation's other ground combat force, has managed to sidestep much of the running feud, and its officers have been less vocal about the controversy over the Iraq war plan. Although the Marine Corps has controversial acquisition programs -- most notably the V-22 tilt-rotor aircraft -- it hasn't crossed swords over any programs as the Army has with Rumsfeld over the Crusader.

The Marines also have fared better in Rumsfeld's personnel choices. Rumsfeld's aides made it known that they found most of the Army's top generals not innovative enough for the demands of 21st-century warfare, but thought the Marine Corps' top officers intellectually nimble. Most notably, last year, the defense secretary picked Marine Commandant James L. Jones to become the first Marine to serve as the top U.S. military officer in Europe, traditionally an Army slot.

Rumsfeld also selected a Marine four-star general, Peter Pace, to be vice chairman of the Joint Chiefs of Staff, the first time a Marine has held that job. Likewise, although some Marine officers in Iraq have been critical of Rumsfeld's role in shaping the war plan, they have not been as prominent in doing so. Some officers have speculated that the Marines will find a way to beat the Army to Baghdad, even if it means suffering some casualties en route.

Such a rapid Marine thrust would be a far cry from the Pentagon's original plan for attacking Iraq developed shortly after the 1991 Persian Gulf War. It foresaw an overwhelming mass of ground forces.

In his remarks yesterday, Rumsfeld acknowledged that the original battle plan to topple Hussein had been changed dramatically as the Bush administration developed its war strategy over the past year.

But, he said, that 1991 plan -- which envisioned a far larger, more heavily armored and conventional invasion force -- was "old and stale" and "didn't reflect any of the lessons from Afghanistan; it didn't reflect the current state of affairs in Iraq; and it didn't take into account the capabilities of the United States in terms of the shift away from dumb bombs to precision bombs."

Sen. John W. Warner (R-Va.), chairman of the Senate Armed Services, delivered a ringing endorsement of the war plan after meeting with Rumsfeld and Myers on Capitol Hill late yesterday afternoon. He said members of the panel "see no reason at that time for anyone to be in criticism of this program."

Warner also took on retired military officers who criticize the conduct of the war. "You do not see former presidents criticizing a sitting president during a war," Warner said, with Rumsfeld and Myers standing at his side. "And the same way, if they've got constructive criticism at variance with the plan, I think they should confidentially contact their own peers in the Pentagon and share it."

Bush stayed out of public view yesterday. His only announced activity beyond his usual war briefings was to drop by a meeting Vice President Cheney held with Australian Foreign Minister Alexander Downer.

The meeting was arranged after Australian Prime Minister John Howard turned down an invitation, extended by Bush over the phone, to join him at Camp David last week for a summit with British Prime Minister Tony Blair, according to Australian news accounts. Those three nations are supplying most of the allied military power in Iraq. Australia announced yesterday that it will scale down its naval involvement in the war at the end of the month.

On Thursday, Bush will make his third visit to a military installation in eight days when he visits the Marine Corps base at Camp Lejeune, N.C., which was home to 12 of the Marines killed in the war. Seven more Marines from Lejeune have been reported missing

Bush will plunge back into diplomacy in early June when he travels to Evian, France, for the Group of Eight summit of seven leading industrial democracies and Russia.

The meeting, which is likely to produce large demonstrations, will put Bush in the same room with two of the world's most vocal opponents of his Iraq policy, French President Jacques Chirac and German Chancellor Gerhard Schroeder. Russian President Vladimir Putin also has been critical. The White House has not announced the trip but when asked yesterday about the France visit, an administration official said, "No changes in the president's plan."

Aides for Cheney said he would postpone a planned two-week visit to Asia because of pressing war demands.

Staff writers Thomas E. Ricks and Mike Allen contributed to this report.

Air Force Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff, says that outside criticism of the U.S. battle plan in Iraq is "bogus." Defense Secretary Donald H. Rumsfeld talks with reporters after meeting with congressional leaders yesterday. At left is Air Force Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff, and at right is Sen. John W. Warner.As the 3rd Infantry Division prepares for an offensive in Iraq, an Army M1 Abrams tank sits in a forward position in central Iraq as an AH-64 Apache helicopter is silhouetted in the setting sun.