Raids on Troops Signal Second Phase of Air War : Tactics: A major goal of the bombers is to knock out Iraq’s elite Revolutionary Guards.

New U.S. attacks against troop formations and equipment in the field signal the opening of a crucial second phase in the campaign to cripple Iraqi President Saddam Hussein and drive his forces from Kuwait.

Like the attacks that Americans have witnessed in spectacular television footage of Baghdad’s night skies in recent days, the air war will continue to feature high-tech surgical strikes.

But the massive air blitz of the initial two days emphasized the destruction of Iraq’s air defenses, command-and-communications centers, missile sites and the most terrifying feature of Hussein’s war machine--chemical weapons plants and nuclear technology.

Although the first phase of attacks destroyed only about 10 of Iraq’s roughly 700 planes, Pentagon officials said, it did destroy runways, control towers and command-and-communications centers essential to their deployment.

The number of Iraqi planes potentially available leaves unanswered the question of whether Hussein’s air force might still pose a threat. But Lt. Gen. Thomas W. Kelly, director of operations for the Joint Chiefs of Staff, said Friday the alliance “is proceeding toward” mastery of the air. Even if some Iraqi planes are able to launch, most are not considered a match for U.S. and allied planes in aerial combat.

Now, as U.S. Marines and soldiers move into position for a ground assault, the raids are zeroing in on Hussein’s ability to sustain his forces in the field.

Although allied pilots continue to place their priority on destroying Scud missiles--a goal they hope to accomplish quickly--the overall emphasis is shifting to pounding roads, fuel and ammunition depots and the troops themselves to isolate them and weaken their ability to defend against a U.S.-led thrust into Kuwait and Iraq.

Many of those strikes will seek to paralyze Iraq’s elite Republican Guards--a blow that would not only deprive Iraq of its best-trained, best-equipped forces but would presumably devastate the morale of lesser units.

“We must maintain the capability to take the ground we said we would take,” Kelly said. “That large army is still sitting there and has to be routed out.”

Losses in the expanding air war mounted to eight aircraft Friday. But as U.S. and allied planes begin their siege on the fuel and ammunition dumps that are keys to the forward movement of Iraq’s most capable soldiers, the warplanes continued to encounter unexpectedly light resistance from Iraqi aircraft and air defenses.

Instead, Hussein continued to fight back with the most powerful weapon he has so far demonstrated against the U.S.-led coalition: bluster and unpredictability.

Iraq’s launch of Scud missiles against Israel in a bid to widen the war underscored Hussein’s ability to disrupt and frustrate the best-laid plans of Operation Desert Storm’s commanders. His gambit spurred an intensified effort to find and destroy Iraq’s remaining mobile Scud launchers, 11 of which were apparently destroyed Friday.

“We are doing the best that we can to suppress” the Scud missiles, said President Bush. “But this man is not going to pull a victory off by waging terrorist attacks.”

The President and his commanders warned, however, that Operation Desert Storm could last longer and suffer more setbacks than its initial successes might indicate.

Although a ground campaign to dislodge Iraqi troops is still planned, defense sources said the aerial bombardment intended to soften up Iraqi defensive lines will continue at least a week or more before the U.S. ground troops will attempt any offensive.

Bush hinted at this strategy Friday, saying: “This will take some time. We can’t expect to overcome it overnight, especially if we want to minimize the loss of life.”

The strategy began in earnest Friday as U.S. and British aircraft began bombing the support structure surrounding the Republican Guards.

Following a new Army doctrine called “follow-on-forces attack,” the warplanes began hitting the logistic network surrounding the Republican Guards, who are deep in the rear of Iraq’s 540,000-strong defensive lines.

Arrayed across northern Kuwait and into Iraq, the Republican Guards were to be Hussein’s reserve forces, capable of rushing to reinforce weak points along the defensive front.

In this second phase, the alliance is seeking to take advantage of the Republican Guards’ chief vulnerability: their reliance on roads and rails and logistic necessities such as fuel and ammunition.

The fuel and ammunition supply areas targeted in the attacks “provide a very lucrative target,” Gen. Charles A. Horner, commander of the Persian Gulf air war, said Friday in Riyadh, Saudi Arabia. “We’re attempting to take out those key elements. . . . Then we will turn to individual attacks on the ground-based supplies in the Kuwait area.”

In an escalation of force planned for the coming days, many of the Navy and Air Force fighter-bombers that have hunted for Scud missiles and pitted airfields are expected to turn to peppering rail lines, switching yards and bridges, as well as assembly areas for tanks and infantry fighting vehicles. The transportation sites are key to the Republican Guards’ strategy of rushing in wherever needed.

“If the Republican Guard can be disrupted, it will make the grand battle much, much easier,” a senior Pentagon official said.

If Republican Guards are able to reinforce weak points at the front, the infantrymen dug into the trenches near the Saudi border--many of them poorly trained, equipped and supplied--would be cut off, officials said.

“If the Republican Guard folds, our hope is that maybe those in the trenches will give it up. We don’t want to have to destroy their whole army if we don’t have to,” the Pentagon official added.

REDIRECTING THE AIR WAR

U.S. military forces are launching a new phase in the air war against Iraq. Rather than narrowly selected targets, the new phase calls for attacks aimed at disrupting supply lines to Iraqi troops. New targets will include:

Concentrations of elite Republican Guards

Roads and bridges

Rail lines

Rail switching yards

Fuel dumps

Ammunition supplies

Food and water stockpiles

Assembly areas for tanks and infantry fighting vehicles