Not long ago, Serbian police were all but confined to the center of this hilly town. To venture beyond was to risk being shot by ethnic Albanian guerrillas of the Kosovo Liberation Army, which dominated the Drenica valley here in central Kosovo.

Now the nearby country roads are occupied by police and Yugoslav soldiers, who maintain checkpoints along them and travel them regularly. Even civilian motorists can pass -- although with a stiff warning that KLA snipers are still at large.

Reclaiming control of Srbica and the Drenica region is one of the main achievements of the Serb-dominated Yugoslav army in its war with the rebels on the ground and NATO planes in the air. Through sweeps across large swaths of Kosovo, accelerated when NATO began bombing in late March, Serbian forces have driven thousands of guerrillas out of the country or deep into border and mountain areas. Hundreds of thousands of ethnic Albanians have been forced into exile.

The Yugoslavs' offensive has drawn down upon them a sustained aerial bombardment by the world's most powerful military alliance. Yet, so far, they appear to consider the punishment from NATO a price worth paying. They show no signs of surrendering. Moreover, they emphasize that if they retreat, it would mean handing over Kosovo to the rebels they've gone to such trouble to suppress.

Over coffee at a police bunker in Drenica, a brawny officer offered a succinct view of the future. "If we leave, the KLA will be back, just like that," he said with a snap of his fingers. "This is our problem. No matter how many we kill, there can always be a loose one or two around to cause trouble."

This widely shared belief makes NATO demands for a full Yugoslav withdrawal from Kosovo -- a cherished, historic part of Serbia -- seem fanciful to Serbian ears. Officials in no way trust NATO pledges to disarm KLA rebels. On the contrary, they believe that NATO is in league with the guerrillas and means to open the way for them to reenter Kosovo in force.

In Drenica, once a major rebel stronghold, the war's terrible cost is visible everywhere. A landscape of burned, roofless houses stretches as far as the eye can see. Ethnic Albanian villages are eerily deserted, fields are unkempt and herds of ownerless horses and untethered cows graze as if wild.

Here in Srbica, police operate, but every other municipal service is a shambles. Both Serbian civilians and remnants of the ethnic Albanian community live in pitiable conditions. Electrical power is out, the result of NATO airstrikes on the energy infrastructure. Townsfolk carry buckets and plastic bottles through dusty streets to water wells. Flour, bread and milk arrive by truck, but not much else. A chicken is worth gold.

In more than two weeks in Kosovo, this correspondent has traveled along main roads through about two-thirds of the Connecticut-size province, sometimes with escort, sometimes without. Because of Yugoslav worries about giving secrets away and the remoteness of some combat areas, it is difficult to fully assess the damage done by NATO and the chances that the air assault will soon force the Yugoslavs to submit. Reporters have been unable to obtain permission recently to visit the front in western Kosovo near the Albanian border, where NATO bombing has been especially heavy.

Nonetheless, it is evident that the Yugoslavs have taken steps to hold out as long as possible. The estimated 40,000 troops and police have responded to the high-tech air assault by spreading out -- serving both to block a KLA return and to minimize damage from airstrikes.

These are not forces massed for attack. They are units in small groups, hiding in every available building, dug into trenches, traveling in every available vehicle -- in short, hard targets to identify and hit. Camouflage is the order of the day. Over there -- is that a tank or a plastic mock-up with a broomstick muzzle?

Army sharpshooters in fatigues continue to pursue remnants of the KLA in the woods and hills. Flak-jacketed police keep an unfriendly eye out for infiltrators, whether in empty or populated towns and villages. Despite weeks of Western efforts to cut off fuel supplies and roads, troops and police seem to have little trouble getting around.

That is not to say the airstrikes take no toll. Somber obituaries stapled on trees attest to the danger to soldiers and police from "NATO aggressors" or "NATO criminals," as the notices portray the bombers. Even NATO blunders can be dangerous for the Serbs: Strikes on a prison at Istok took the lives of up to 50 ethnic Albanian inmates but also killed 30 police and guards, Serbian sources said.

The other day in western Kosovo, the sight of an A-10 bomber from NATO's arsenal cutting lazy circles in the sky sent police scattering from a roadside position into open fields.

The roar of NATO jets sounds night and day. For someone standing perhaps a mile from a hit, the experience is like this: a sudden jet's heavy roar, as if it were diving; a flash; then a crackling boom and a brief, jolting wind from the point of impact. The view is equally startling: bilious clouds of smoke, debris tossed scores of feet in the air, perhaps a fire.

On Tuesday evening, NATO jets swooped over Pristina, the provincial capital, and dropped 15 bombs beyond the city's hills. The impacts lit up the skyline, rattled windows and set off burglar alarms deep into town.

In Pristina yesterday, it was not bombs but leaflets that were dropped by a pair of B-52 bombers. They warned Yugoslav soldiers to leave or face "thousands of bombs."

"NATO is now using B-52 bombers for launching MK 82 225-kilogram bombs on Yugoslav Army units," read the leaflets, which included a fuzzy picture of a B-52 dropping dozens of bombs. "Thousands of planes will be back to get you. If you want to survive and see your family again, leave your unit and equipment and leave Kosovo immediately."

Foreign correspondents are rarely shown military destruction. One day, reporters were taken to a bombed house portrayed by guides as a civilian site -- ignoring the nearby, charred, oddly shaped vehicle with twisted antennae.

In casual conversation in Pristina cafes, soldiers inquire eagerly about the progress of peace efforts. In an interview Friday, Maj. Gen. Vladimir Lazarevic, whose Pristina Corps leads the fighting here, expressed displeasure that NATO bombing seems to escalate when diplomacy gets into gear.

The yearning for peace grows in part from the fact that the KLA has not been routed completely. Early last week on Mount Cicavica northeast of Pristina, rebels tossed a hand grenade onto a tractor carrying two policemen, killing them. Even sniping occurs in Pristina.

Lazarevic accused the alliance of urging Albania to support the KLA with artillery fire into Kosovo and of launching airstrikes to help the guerrillas infiltrate Kosovo. He said that if NATO is serious about disarming the rebels, it ought to start in Albania.

One informed Serbian observer said that in recent weeks, NATO undertook a systematic bombing campaign of Yugoslav army positions along three north-south lines between Djakovica and Pec and eastward. The goal, this analyst said, is to open the way for the KLA to move from bases in Albania back to Drenica.

Yugoslav officials are clearly preoccupied by suspicions of a NATO-KLA alliance -- the subject of an unusual press outing Tuesday to Gnjilane, a city southeast of Pristina not far from Macedonia. There, Yugoslav officials presented three ethnic Albanians accused of spying for NATO -- Sabit Hoxha, Fadih Kalaba and Nijazi Ajdari.

Yugoslav investigator Zivorad Stankovic said the men had phoned NATO by portable satellite telephone and pinpointed military targets at the city of Urosevac. Stankovic exhibited diaries and maps allegedly prepared by the men. On the maps, command posts, bridges and other landmarks were detailed.

"They are arrested for acts of espionage. They gave out confidential information and intelligence on the whereabouts and movements of police and army units. Based on the facts provided by these persons, NATO bombed Urosevac and caused great damage," Stankovic said.

CAPTION: Smoke could be seen from a distance when Yugoslav forces burned houses in the Drenica region in March as part of a stepped-up campaign against the Kosovo Liberation Army. Below, Serbian police left Drenica as a house burned behind them. The accelerated hostilities led international monitors to withdraw to Macedonia, and NATO began bombing shortly thereafter.