`ATTACK, DISRUPT...DESTROY; AIRSTRIKES CONTINUE TO HIT MILITARY SITES IN YUGOSLAVIA.

Byline: Francis X. Clines The New York Times

Yugoslavia withstood a second wave of NATO air assaults Thursday, with the White House vowing prolonged and severe attacks while Yugoslav President Slobodan Milosevic was reported to be defiantly stepping up his military campaign around Kosovo.

``He's escalated today,'' said Sandy Berger, President Clinton's national security adviser, conceding that despite the NATO assault, Milosevic's military forces continued their sweep, burning ethnic Albanian villages in Kosovo and even sending ``some shelling'' into nearby Albania.

``It's very disturbing to us,'' Berger said at a White House briefing. But he declined to speculate on the motives of the Yugoslav leader, who has rejected NATO demands that he cease hostilities against the ethnic Albanian separatists of Kosovo.

As fresh salvos of missiles and bombs struck targets in Yugoslavia, the NATO supreme commander, Gen. Wesley Clark, resolutely vowed that the duration and severity of the military campaign was up to Milosevic.

``We're going to systematically and progressively attack, disrupt, degrade, devastate and ultimately, unless Milosevic complies with the demands of the international community, we're going to destroy his forces,'' Clark said at NATO headquarters in Brussels, Belgium.

On the second straight day of NATO bombardment, cruise missiles and guided bombs rained down on targets that Pentagon officials described as military and air depots and factories underpinning the yearlong assault against Kosovo, the southernmost province in the Serbia republic, which is Milosevic's power base as Yugoslav leader.

``It will be another substantive strike; it will be severe,'' said Pentagon spokesman Kenneth Bacon as the bombing was renewed from an armada that includes six warships and roughly 400 bombers and fighters. He said the latest attacks were ``principally on air defense targets and military targets'' that are being used in the repression of the province's ethnic Albanian majority.

Defense Secretary William Cohen expressed satisfaction with the effectiveness of the NATO raids, but declined to discuss any strategic timetable. ``The Serb forces should not take any comfort that they could be free from any sort of assault or attack from our forces at any time during the course of the day or night,'' he said in an interview on public television. ``It could be done at any time.''

With Western news workers ordered to leave Yugoslavia, there were no detailed accounts of target destruction in the latest bombing run. More than 40 targets were hit in the Wednesday assault, Pentagon officials said, amid unofficial speculation that the Thursday attack might have been even more ambitious in its target plan.

In Belgrade, the Milosevic government insisted it was the innocent victim of NATO aggression. Deputy Prime Minister Vuk Draskovic talked of possible compromise in news interviews, but no such talk was heard from Milosevic, Belgrade's authoritarian ruler who has rigidly rejected calls for a cease-fire. ``Stop bombing us,'' Draskovic contended on Britain's Sky TV, ``and we will stop all operations against the people, the terrorists who provoked NATO strikes against Serbia.''

In Skopje, Macedonia, near Kosovo's southeast border, thousands of Serb sympathizers marched on the American Embassy, throwing rocks and torching cars in protest against the NATO raids and in support of Milosevic.

``He must either choose peace or we will limit his ability to make war,'' President Clinton said of the Yugoslav leader in brief White House comments amid a busy day of military briefings. Various administration officials carefully stressed the goal was not to knock Milosevic from power but to force him to observe Kosovo peace promises he made, then broke, last year.

Russia's threats

Asked about Russian threats to lift the arms embargo on Yugoslavia, Clinton declared, ``I think that would be a terrible mistake.''

The administration's concern over Moscow's angry denunciation of the NATO raids was emphasized by Secretary of State Madeleine Albright at a briefing. One of the administration's main diplomatic goals now that airstrikes are under way, she said, was ``maintaining contacts with Russia and making clear that our differences over Kosovo need not disrupt progress on other fronts.''

Warning Milosevic against widening his military campaign to the surrounding region, Albright said plans were being made for ``a flood of new refugees.'' She said ``Milosevic's forces in Kosovo are today continuing their offensive against civilians, burning and looting and attacking political leaders.''

With Republican critics questioning whether the administration has a strategic alternative to bombing, Berger defended the NATO air assault, insisting that Milosevic ``will sustain the most serious damage if he thinks he can ride out an air attack.'' Even more, he underlined Clinton's assertion that the operation will not see the commitment of U.S. fighting forces on the ground.

``That is something we do not intend to do,'' Berger declared.

Precedent for NATO?

Facing news reporters, the president's security chief was asked whether the 19-member NATO assault has now established ``a precedent for intervening in civil wars.''

``Every situation has to be taken on its own merits,'' Berger replied, maintaining that Milosevic presents ``a rather weak argument'' in invoking sovereignty after his record of hostilities in Croatia, Bosnia and Slovenia.

``The president has said many times that it depends upon whether America's national interests are involved, as well as our values,'' Berger continued. ``Our values are involved in preventing what I believe would be a humanitarian catastrophe. Our interests are involved in avoiding a wider conflict in southeastern Europe, which I think would most likely involve us at some later point with far greater costs and at far greater risk.''

The president has argued that the 19-member NATO alliance has a moral obligation to deal with the Kosovo onslaught, terming it Wednesday a ``powder keg at the heart of Europe'' that will endanger neighboring nations unless Milosevic is stopped in his campaign of ethnic cleansing and atrocity against the Kosovar majority. An estimated 2,000 people have been killed in the past year, with hundreds of thousands of ethnic Albanians driven from their homes.

Clinton's defense

Looking haggard and sounding weary, Clinton brushed aside signs that the nation is divided over U.S. participation in the NATO bombing.

``I believe that many Americans really have not thought a lot about this until the last two days,'' he told reporters between military briefings. ``I also believe very strongly that it is my responsibility to make this judgment based on what I think is in the long-term interests of the American people.''

A CNN-Gallup-USA Today survey released Wednesday showed that 46 percent of Americans support the nation's participation in the bombings while 43 percent oppose it. A CBS News Poll released Thursday showed that 50 percent favor the intervention and 30 percent oppose it, but it also showed that 52 percent said that peace in Yugoslavia was not worth the price of American lives. About one-third said peace was worth that price.

The White House indicated Clinton's appeal for public support in the risky military assaults would be ongoing across the NATO action, which thus far has not been described as subject to a specific time limit. ``I don't believe last night's address to the nation was the last thing the president needs to say,'' said White House spokesman Joe Lockhart.

Clinton said he believed that a majority of the public would support the case he laid out in his 13-minute address to the nation Wednesday night. ``I did my very best to explain what we were doing and why,'' he said.

In Congress, Sens. Mitch McConnell, R-Ky., and Joseph Lieberman, D-Conn., unveiled legislation to authorize $25 million to train and arm Kosovars in defense of the ethnic Albanians. Lieberman said he hoped the airstrikes would produce peace in the Balkans. But if it does not, he said, the arms proposal answers the question of what might be an exit strategy from Kosovo. But McConnell conceded that, in recently bringing up the proposal with the president and other administration officials, the only reaction was ``stunned silence.''

At his security briefing, Berger rebuffed suggestions that NATO was disunited in the raids. He said comments by Italian Prime Minister Massimo D'Alema about the urgent need for diplomacy seemed based on the erroneous impression that the fighting in Kosovo had ended. ``We'll obviously point that out to him,'' Berger said, adding: ``There are varying perspectives in any alliance, but I believe that there is clarity and solidarity about this mission.''

CAPTION(S):

3 photos

PHOTO (1 -- color) A pall of smoke rises from civilian buildings Thursday near Yugoslavian military barracks in Pristina as NATO air attacks continue.

Thierry Charlier/Associated Press

(2 -- color) Gen. Wesley Clark, NATO supreme commander, speaks at a press conference in Brussels, Belgium.

Senior Airman Jeffrey Allen/U.S. Air Force

(3 -- color) An A-10 Thunderbolt pilot gives a thumbs-up sign before takeoff in Aviano, Italy, on Thursday, the second day of attacks on Yugoslavia.

Mikica Petrovic/Associated Press