For the first time since the Persian Gulf crisis began more than four months ago, the Bush administration warned publicly this week that a full-scale ground war would be the centerpiece of its military strategy if force becomes necessary to eject Iraq from Kuwait.

Such a strategy would reject relying solely on surgical air strikes, massive carpet bombing and other "nice, tidy, allegedly low-cost, incremental, may-work options that are floated around with great regularity all over this town," as Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, put it in congressional testimony.

Instead, Powell and other senior officials left the clear impression that the administration currently regards a violent, bloody, overland war -- possibly involving the greatest tank battle in the history of warfare -- as the only certain means of destroying Iraq's army or forcing it to retreat. Air power, although vitally important, would not be enough under this view.

That message was obviously directed in part at Iraqi President Saddam Hussein, but it coincides with the strong preference of senior U.S. commanders. Final decisions about the kind of attack the United States might launch would ultimately be made by President Bush.

Winning a combined air-and-land war presumes that U.S. air power would control the skies from the first day and would continue to pound Iraqi strongpoints and communication centers day after day. It also presumes that fast-moving U.S. forces guided by up-to-the-minute intelligence on enemy deployments would have the advantage of surprise attack, and that dug-in Iraqi forces would remain comparatively immobile and unable to patch holes that allied forces punch in their defenses.

Pentagon officials say this U.S. war-fighting strategy is likely to have several consequences:The war would last months, rather than days or weeks, unless Saddam unexpectedly surrenders. Adm. William J. Crowe Jr., former chairman of the Joint Chiefs of Staff, said the air campaign could last from 30 to 45 days.

U.S. casualties would number in the thousands, rather than scores or hundreds.

Before the first shot is fired, Powell and his generals will be confident enough of victory to assure Bush that Iraq would be ousted from occupied Kuwait. "We can't guarantee the price, but we can guarantee the outcome," one Pentagon official said this week.

Some Pentagon planners believe the administration's tough, graphic rhetoric in testimony this week may have influenced Saddam's move to release his Western hostages. Even so, Bush's chief political objective -- the liberation of Kuwait -- remains unfulfilled, and military tacticians continue to burnish the war plans they expect to use if diplomacy fails.

The plans were drafted by Gen. H. Norman Schwarzkopf, commander of U.S. forces in the gulf, and approved by Powell and the four service chiefs. In part, they reflect a traditional Army belief -- Powell and Schwarzkopf are infantry officers -- in the decisive importance of ground forces in combat. Gen. Michael J. Dugan, the former Air Force chief of staff who was fired in September after describing how to bomb Iraq into submission, is not the only air power enthusiast in the Pentagon. But they are not the ones who have written the war plans.

Testifying before the Senate Armed Services Committee, Powell explained why the United States could not depend on air power alone against Iraq. Although the Air Force could "inflict terrible punishment," Powell said, "one can hunker down, one can dig in, one can disperse to try to ride out such a single-dimension attack." Relying on air power also would leave the initiative to Saddam and permit the Iraqi leader "to concentrate essentially on one threat . . . an air threat."

Instead, the United States would attack "suddenly, massively and decisively," as Secretary of State James A. Baker III said Wednesday, with forces from all four services. "We want to offer the enemy the opportunity of selecting one of a large number of ways to die," a Pentagon official said shortly after Baker's testimony before the Senate Foreign Relations Committee.

Although the specifics of Schwarzkopf's war plan remain classified, military officials said certain fundamentals for combating an army like Iraq's that is equipped with modern armor and artillery must be followed if war is launched. War plans are not written in all-or-nothing terms, but offer options for a president to choose. Bush, however, has said he has discarded the option of applying force incrementally, as was done in Vietnam, and intends to order an all-out campaign if a war must be fought to get Saddam out of Kuwait.

Victory in war, particularly in desert fighting, depends as much on timing, maneuver and innovation as on weapons and numbers. Powell this week spoke of a strategy "that uses our strengths against their vulnerabilities {and} avoids their strengths." U.S. strengths include vastly superior night-fighting capability; superior intelligence-gathering and electronic warfare skills; a force that is almost entirely mobile; and virtually certain dominion over the skies and seas.

Although Iraq has strength in numbers with 480,000 troops in and around Kuwait, about two-thirds are relatively immobile, lightly armed infantrymen. By adding another quarter-million soldiers to that force, as Saddam has vowed, U.S. planners believe the Iraqi leader will reap diminishing returns by taxing his logistical lines, weakening his borders elsewhere and providing only a modest increase in firepower.

"Two hundred and fifty thousand men with nothing but rifles can get lost in a few miles of desert," a senior officer said recently. "If they could double the {elite} Republican Guards, we'd be worried. If they could come up with another two armor divisions, we'd be worried. But they can't."

Armies fight the same way they train -- they do not make up their tactics as they rumble through the dust clouds of the desert in tanks and armored personnel carriers on the way to their objective. According to military officials, the plans for fighting Iraq are almost certain to include these phases:Phase One

Unmanned Navy Tomahawk cruise missiles and about 40 Air Force F-117A "stealth" fighters would target the Iraqi air force's command and control network to deny Iraqi pilots radio guidance from ground controllers tracking U.S. planes. Scores of Air Force F-111 fighter-bombers based in Turkey and carrier-based Navy A-6 attack bombers would follow by firing missiles, like the HARM and Tacit Rainbow, that destroy radar antennas by homing on radar signals.

Air Force F-15 and F-16 fighters, guided by AWACS (Airborne Warning and Control System) aircraft, and Navy F-14s and F/A-18s, guided by AWACS or the E-2C Hawkeye, would try to sweep the sky of Iraqi planes, while U.S. bombers strike virtually every airfield in Kuwait and Iraq that could be used by Iraqi warplanes. The bombers would try not only to destroy enemy planes still on the ground, but also to carve such large holes in the runways that planes hidden in hardened bunkers cannot take off later.

The munitions dropped would include earth-penetrators and cluster munitions. The penetrators have delay fuses that detonate periodically after the raid has ended, greatly complicating the task of repairing runways. Cluster munitions the size of tennis balls would litter the runways and explode in a deadly spray of steel pellets if disturbed by Iraqi repair crews.

Electronic warfare planes and other high-tech jamming gear would try to disconnect Iraq's top commanders from forward units.

This vision of the opening phase of the war hinges on tactical surprise that immediately gives U.S. forces the initiative. Planners continue to fret over a preemptive "spoiling" attack by Saddam. "There goes the neatness of our operation," a Pentagon official said this week, "if he wrests the initiative from us." Saddam also has mined Kuwaiti oil fields and wellheads, according to Crowe, the former chairman of the Joint Chiefs, so any attack would likely trigger the widespread destruction of Kuwait's principal industry.Phase Two

With the Iraqi air force largely destroyed, the ground war would begin in earnest. Army units and Marines offshore would try to confuse Iraqi defenders with feints, deceptions and continued electronic jamming. Saddam "essentially has tried to barricade the whole country of Kuwait on two sides, the east and south. He has bought himself a huge logistical burden," a Pentagon planner said. "He has to be strong everywhere."

Air Force B-52s would drop hundreds of tons of munitions on Iraqi artillery bases, command posts and supply roads. Now based at Diego Garcia in the Indian Ocean, the bombers would move to an airfield nearer the front under an arrangement already made with an allied Arab government, according to Air Force sources. Unlike Vietnam where heavy jungle hid enemy strongholds and supply lines, the treeless desert of Kuwait and Iraq offers little cover.

The B-52s could also be used to obliterate Iraqi nuclear, chemical and biological weapons plants. But such attacks would likely kill hundreds of civilians, and it is unclear whether Bush would authorize destruction of these facilities. Smaller Air Force and Navy bombers would strike barracks, bridges, motor pools and tank formations.

To exploit these air strikes while enemy forces are still "stunned and disoriented," U.S. doctrine calls for a coordinated ground attack to follow the bombers almost immediately. As U.S. troops rush forward, low-level air attacks by A-10 tank-killing planes and Apache helicopters would be launched against Iraqi armor and "Bimps," Soviet-made BMP infantry vehicles.

To prevent Iraq from reinforcing the areas threatened by U.S. spearheads, "we're placing a great premium on restricting their mobility," largely by keeping enough warplanes overhead to annihilate enemy forces that emerge from reinforced bunkers, the officer added.

U.S. analysts studying Iraq's eight-year war against Iran also believe that Iraqi army units lack the independence and initiative to operate effectively without precise direction from regimental leaders. So Pentagon planners want to isolate Iraqi units from their regimental commanders in hopes of provoking mass surrenders or at least feeble fighting.

Military planners know that even if the United States surprises Iraq and keeps the initiative, things would go wrong. Low-flying planes and helicopters are vulnerable to Soviet-made SA-6 and SA-7 antiaircraft missiles, which Iraq has in considerable numbers. In combat, troops almost always fire inadvertently on their comrades at some point. The complex choreography required by U.S. battle tactics is further complicated by the presence of tens of thousands of allied troops in Saudi Arabia, although a congressional source says that Schwarzkopf would act as supreme commander, an arrangement being kept quiet to avoid ruffling Arab sensibilities.Phase Three

No matter how much the Air Force and Navy bomb, Army leaders warn that it would eventually come down to soldier-against-soldier before the Iraqi army could be rooted out of heavily fortified positions in Kuwait.

U.S. planners have basically scrapped the traditional 3-to-1 attacker-to-defender ratio long considered necessary to overcome fortified positions; U.S. mobility, air strength, firepower and other advantages provide "force multipliers" that compensate for raw numbers, they say. Powell this week said that "by pushing for a combined air, land, sea campaign, we are {not} adopting a strategy of cannon fodder where we are just going to run into fortifications without thinking our way through this."

Nevertheless, Saddam's buildup in the desert west of Kuwait means the U.S. armored force cannot simply outflank the Iraqi army and envelop Kuwait. "We would have to puncture his fortifications someplace," one officer said.

"You can never get them out with just air power. You can bloody them, you can kill a lot of them, but you cannot dominate them," a Pentagon source said this week. "And you cannot capitalize on air power unless you pursue it on the ground."

The typical Iraqi defensive position in Kuwait is laid out in a triangle. A fortified firing position with machine guns sits at each corner of the triangle. Infantrymen are stationed between these corner strongpoints in protected foxholes. The rear corner of the triangle is armed with mortars and artillery batteries which fire over the heads of the front-line defenders. Tanks are dug in to the side of the corner strong points facing the invaders.

These triangular forts are protected along the frontal approaches by barbed wire, hundreds of mines and deep antitank ditches that can be filled with fuel oil and set ablaze. One standard tactic for breaching these fortifications is a high-speed night attack using tanks, rocket-equipped vehicles and Bradley Fighting Vehicles filled with infantrymen.

With M-1 tanks forming the spearhead, the attacking column would fire rockets and shells to confuse, blind and kill the heavy weapons' operators in the rear of the triangle. At least two M-1s would swing away from the attacking column to duel the Iraqi tanks flanking the triangle.

Another M-1, with a heavy roller attached to its front, would rumble toward the center of the triangle. Designed to trigger mines, the roller would soon be twisted out of shape and other M-1s with rollers would follow to finish clearing a pathway to the edge of the ditch. There, an M-1 with a plow would fill in the ditch, making a road leading into the heart of the triangle.

A weapon which resembles thick rope with explosives hanging along it would then be fired out of a barrel. Called a Mine Clearing Line Charge, the rope of explosives would extend along and beyond the pathway made by the M-1 tanks. The explosives would set off mines beyond those detonated by the M-1 mine rollers.

Next, M-1 tanks would race along the mine-free path and smash into the rear fortification. Bradley vehicles would rush along the path behind the tanks, their machine guns and cannon spraying the ditches. Infantrymen would jump out of the Bradleys and fire at surviving enemy soldiers, dangerous work where many attackers almost certainly would be killed or wounded.

Once the triangular defense was breached and destroyed, the M-1 tanks would push through the fortification and race off to attack the reserve force of tanks and enemy soldiers far to the rear of the triangle. The Bradleys would follow the tanks.

Fortifications bracketing the one breached would be left alone until the reserve forces in the rear had been destroyed, a tactic intended to sever the other forward triangles from the support of heavy guns, armored reinforcements and senior commanders.

"We'd be through there before the rest of the line could react," one armor officer predicted.

Where the U.S. offensive drive would go is uncertain. Some analysts believe that driving to Baghdad would be more effective than enveloping Kuwait; others say that after destroying the elite Republican Guards forces being held in reserve north of Kuwait, U.S. troops could strangle Iraqi forces in Kuwait by cutting off their food and fuel. Still others, particularly Army officers, believe it will be necessary, as one said, "to go in and dig them out."

Egyptian, Saudi and Syrian armored forces would be used to hem in Iraqi troop concentrations while faster U.S. forces would race around flanks and take up blocking positions to chop the Iraqi army into vulnerable chunks at many points.

Powell took pains this week to stress that the Joint Chiefs, who have met formally 30 times since Iraq invaded Kuwait on Aug. 2, unanimously support the U.S. battle plan. The chiefs discussed the strategy with Bush at Camp David on Dec. 1 during more than three hours of talks.

Staff writer Barton Gellman and staff researcher Lucy Shackelford contributed to this report.