WITH U.S. FORCES, SAUDI ARABIA, FEB. 5 -- Over almost three weeks, the air war in the Persian Gulf has become a grim symphony of destruction.

Composed of more than 47,000 sorties by aircraft from a half-dozen nations, flying more than two dozen different kinds of aircraft, it has shot or dropped everything from laser-guided bombs to leaflets urging immediate surrender and suggesting how it might be done. And by all accounts, official and anecdotal, the record is impressive.

All of Iraq's nuclear, biological and chemical warfare infrastructure are said to have been eliminated; command and control severely crippled; countless defense industries, fuel dumps, ammo dumps, Scud missile sites and airfields all but destroyed. There is little collateral damage, military briefers say, because planes can drop "smart bombs" like the ones that cut a bridge but scarcely ripple the river beneath.

This macabre artistry, however, is not what will decide when -- or even if -- Operation Desert Storm will become a ground war, commanders say. That decision will come only after allied warplanes have had a chance in the next few weeks to destroy Iraq's 500,000-man army, its 4,000 tanks and its 2,500 armored personnel carriers -- a fighting force mostly entrenched behind elaborate fortifications in Kuwait and southern Iraq.

The effort to obliterate the Iraqi army began in earnest last week.

"Can you imagine if . . . they'd been dropping bombs on us like three or four times a day?" said Air Force Col. John McBroom, commander of the 1st Tactical Fighter Wing from Langley Air Force Base in Virginia. "If you have lived through that, you're not in a good mood, you don't feel good. If you don't have ringing in your ears, you're probably very lucky.

"We're taking a very heavy toll on the Iraqis," McBroom said. "Everybody's getting hit up there right now."

But how hard? The idea, military officials say, is to "degrade" or "attrit" -- reduce by attrition -- the Iraqi war machinery to the point where it can no longer function. There is, they say, only one way to do this: Destroy tanks and kill people.

The next two weeks are likely to test this strategy. As "hard targets" -- defense industries, bridges, airports, vital infrastructure -- are eliminated, the allied planes will gather over the Iraqi trenches in ever-growing swarms.

The tools of the trade are many. They include anti-tank bullets made of depleted uranium, one of which can blow a hole in an armored turret and cut an entire crew to ribbons as it rattles around inside. Then there are the B-52s and their 1,000-pound "stupid bombs," whose explosions light up the night sky in northern Saudi Arabia and shake the ground near the Kuwait border where U.S. Marines have dug their foxholes.

"The more we bomb, the less we die," Marine Sgt. Percy Smith, 32, of Atlanta, told combat pool reporters, summing up footsoldiers' sentiments. But, he noted, "I know they {the Iraqis} are catching hell."

This is the ugly part. Air Force Maj. Bob Baltzer, 41, of Dayton, Ohio, said the allies' "goal is to attrit {Iraqi President Saddam Hussein's} military power down to half of what it is before the bombardment." Then, he told another group of pool reporters, the ground war will begin.

McBroom, in an interview today, did not talk about a magic percentage, but he acknowledged that air strikes on Iraqi fortifications were "intensifying . . . every day," in hopes of breaking either the Iraqis' spirit or their capacity to fight -- or both -- before an allied infantry offensive.

"I think all of us would like to see us never go in with ground troops," said McBroom, 46, of Hopewell, Va. "That goes for the Army, that goes for the Air Force -- everybody feels that way. We just think it would be better . . . if we could take them out all in the air. What we would like to do is . . . continue to attrit them at an ever-increasing rate."

Attacks on troops, McBroom said, began in the first days of the war. His F-15C fighters escorted B-52s into southern Iraq, where they dropped 240,000 pounds of bombs on Iraq's Republican Guard, linchpin of Iraq's armed forces and the only troop target given a "first priority" in the allies' bombing plan.

Very quickly the allies established mastery of the air. Since the first day, McBroom's F-15s have not been challenged by Iraq's MiG fighter planes. By the end of the first week, antiaircraft artillery fire and surface-to-air missile (SAM) launches had declined markedly.

"The first things you would take out would be your strategic targets," McBroom said. "And then you start getting into the SAMs and the aircraft, and they come pretty fast too. And then you get on down to your troops."

McBroom said Iraq had a "decent air force, but not a good air force," in that neither its planes nor its pilots could match the F-15s. The Iraqis refused to fight, holding fast in hardened shelters, flying north to remote airstrips, or, more recently, escaping to neighboring Iran. U.S. military officials said today that approximately 110 Iraqi planes are now being kept in Iran.

Meanwhile, allied radar-attacking missiles had begun to intimidate SAM gunners, who could turn on their radar and risk being hit with a missile, or turn them off and shoot "stupid."

"We lost a few aircraft early on, to SAMs and triple-A {antiaircraft artillery}," McBroom recalled. "That has decreased as we've gone along."

By the end of January, the allies were able to fly anywhere in Iraqi airspace whenever they wished, briefers have said. Virtually the only Iraqi aircraft in the sky were those on their way to Iran. The number of the F-15s' direct escort missions dropped somewhat, to be replaced by "combat air patrols" -- airborne sentry duty conducted on the very edge of Kuwait.

The bombers continued to hit Scud launchers, truck convoys and the Republican Guard -- finally bringing the war to the trenches of Kuwait. Bombing today, McBroom said, is "walking its way down" from the Guard south to the Saudi border.

"You know, we had a list {of targets}," McBroom said. "We crossed off number one, number two, number three, number four. We're hitting everywhere."

The accounts of the air war given so far by allied officials have dwelled on its exploits. Such setbacks as Iraq's early success at preserving mobile Scud launchers and the inadvertent destruction of a U.S. light armored vehicle by a U.S. warplane last week -- killing seven Marines -- have been described by the military as troubling but not representative of the entire campaign.

In addition, journalists in Baghdad have reported that allied bombs and missiles have hit non-military areas there. U.S. officials have said any damage may have been caused by missiles hit by antiaircraft fire or may be the consequence of Iraq's practice of locating military and industrial facilities near residential areas.

McBroom's job is to stalk the Iraqi air force, a challenging task but, so far, not a very dangerous one. Besides the Iraqi planes in Iran, McBroom believes the Iraqis have hidden several fighters in residential neighborhoods -- an allegation echoed by military briefers -- and still have large numbers in hardened shelters and in northern airfields.

"He {Saddam} hides the aircraft, and he's very good at that," McBroom said. "If they decoy them, hide them, put them in bunkers, etc., they can save them to fly another day, at least until we find them and kill them."

McBroom said a single Iraqi fighter might be able to sneak through the allies' airborne security screen to drop poison gas or strafe infantry positions, but he discounted any mass air assault. Iraq has no airfield left, he said, where several hundred warplanes could be refueled, serviced or given space to take off at the same time.

"I don't think he can muster a game plan. I don't think he has the comm {communications} or anything else to do that," McBroom said. "Plus, I don't think he has the people to do it. I don't think his pilots really want to get airborne."

So the latest -- and perhaps last -- phase of the air war has begun. Efforts to interdict supply lines have been somewhat disappointing, McBroom said, the object being to reach the point where Saddam "cannot supply his troops. I think we're well on the way, but we're not there yet."

Dummies and decoys -- of airplanes, shelters and vehicles -- are an irritation. "You know" if it's a decoy, McBroom said, "by whether it blows up or not." But in the end these won't matter, he added, because Saddam is "going to lose all his decoys, all his airplanes. We'll take out everything."

But the great imponderable remains the bombing of soldiers, equipment and fortifications, an utterly ruthless business with one objective: "I would hope that we do not go in on the ground until we have just almost completely obliterated them," McBroom said.

"And that's from a selfish standpoint," he added. "I'd just hate to see sending young Americans into war. I would like to see us stand back and do it with our smart bombs and our technology. I think we can do that. . . . I'm saying we ought to go with the air power for a while. Let's ride this horse as long as we can."