BUDAPEST, Hungary -- Wednesday was the night NATO went to war and Yugoslavia reaped a whirlwind.

After days filled with rumor and tension, after nearly 10 years of ethnic conflict and more than 600 years of rancor over faith and land, modern war, with all its surface pyrotechnics and devastating force, was unleashed Wednesday from the skies over Yugoslavia.

With an orange burst over the horizon, the first cruise missile announced its arrival near Belgrade. What had once been unimaginable -- the first allied airstrikes against a sovereign European country since World War II -- became reality.

The citizens of Yugoslavia were plunged into a twilight zone.

Foreign journalists, the spectators who always are going into places that everybody else is trying to leave, became a part of the story for a while.

It's creepy being in detention while air-raid sirens wail, bombs drop and a couple of leather-clad secret police saunter around with snub-nosed automatic weapons at the hip.

But that's life in Belgrade under Yugoslav President Slobodan Milosevic. Bombs can blow apart defense installations, but Milosevic's goal seems to be to quash all dissent and hang on to power, even when confronted by NATO's massed force.

It helps to explain why police made a sweep on the opening night of bombing, herding 29 reporters and photographers off the roof of the Hyatt Hotel, into patrol wagons and down to a local police station for what was essentially four hours of hanging around while officers collected cellular telephones and passports, questioned several people and then released everyone but a Belgian journalist, who was later sent out of the country.

Hotel staff made sure to bring in ham-and-cheese sandwiches.

It was a bewildering, surreal interval. But it was only a glimpse of the kind of terror that is meted out in one of the last old-style communist states in Europe.

The foreign journalists were expelled the next day. Some, by choice, are now back in Belgrade.

But most of the inhabitants of Serbia and its Kosovo province have no choice. As NATO's powerful war-making machine churned toward the moment of terrible punishment for Milosevic, the two populations shared foreboding, but little else.

For Serbs, there was fear and disbelief, anger at the United States and reluctant support for Milosevic, a leader whom few seem to like but whom nobody can get rid of.

In all the Balkan warfare of the past eight years, Belgrade has not been damaged by fighting. So in the hours leading up to the war, people shopped and gassed up their cars. But they also lingered in cafes and enjoyed a last sunny day before bombing.

"There will be nothing," a woman named Radmila said as she walked a dog. "Everything will be good."

Government officials were also in a state of denial. Sitting at a long conference table inside Belgrade's ornate city hall, a Yugoslav government minister named Milan Bozic furiously smoked cigarettes and claimed that the bombing could be averted.

"We are still going to negotiate," he said. "I will find out something in a half-hour. Call me."

By then, though, NATO was revving up its war machine.

The opening salvos could hardly be heard in the city center. The bursts were on the outskirts, flashes illuminating the night sky like fireworks.

And the bombing went on and on, with the sound of war echoing through the streets of the old city at the confluence of the Sava and Danube rivers.

People were now scared.

"On the way home, I was greeted by the tank parked on my street," one citizen said. "I hear this is not unique."

For ethnic Albanians bidding for Kosovo's independence from Serbia, NATO bombs meant that they were at last receiving Western support. But many realized that those bombs would exact an awful price on the ground.

Reporters are normally observers of events. But when war strikes, especially in a place as volatile as the Balkans, the rules can suddenly change. If someone asks which side you're on, the only correct answer is: your own. Yet even your own actions have consequences.

The first inkling that this would be a different kind of assignment came the day before the bombing, when, along with several colleagues, we pulled out of Kosovo's dusty provincial capital, Pristina.

As we said farewell to several local residents, utter terror crossed their faces because we were delivering bad news face-to-face.

They did not fear the bombs. They feared the Serbian security force, the secret police and local hoodlums who would enter the vacuum and start a crackdown of bloody violence against them.

Even in the best of times, Pristina is a grubby little place dumped in a valley, a mass of dust and concrete with tiny shops, dimly lighted cafes, depressing tenements and a university that has a building so hideous that it looks a little like a cancerous mole.

For foreigners, the main place to stay is a dark, seedy hotel that someone had the sense of humor to call "the Grand." Thugs in leather coats hang out in the lobby; when you get a room, you're lucky if someone else's stuff isn't there.

Among the press at the Grand, there was fear that when the bombs dropped, Serbian secret police would strike, which they did, with a vengeance. They hauled away some reporters at gunpoint, rounded up others, delivered a few beatings. In one case, the hotel staff jumped from behind the front desk to help kick.

But the journalists got off lightly.

On the drive out of Pristina and up to Belgrade, it was obvious that Yugoslav forces were ready to move against ethnic Albanians once the bombs dropped. Truckloads of soldiers were ferried across rutted roads, equipment was dispersed and bridges appeared to be mined.

For all of NATO's talk about "degrading" Milosevic's ability to run roughshod over ethnic Albanians, it was clear that local security forces were planning to move quickly against the ethnic Albanian rebels.

And no civilian would be safe.

Now Kosovo is effectively sealed off from the outside world, and there is no way to know the extent of the atrocities taking place there.

Yet here is a clue. In October, several reporters sat in a room in a village named Baice, trying to talk with two silent children who had survived a massacre in which their pregnant mother was butchered like an animal and many other members of their extended family were killed.

Nobody knows what the children saw or heard during the massacre. And nobody knows how they survived.

There is a question that haunts me still: Where do these kids sleep tonight?