Is this the Serb chief's last stand?

As Yugoslavia dwindled in size this decade, President Slobodan Milosevic kept his grip on power by promising that Kosovo, the cradle of Serbian culture, would never be lost. But now, with Kosovo in upheaval and NATO ordering airstrikes following the Serbs' refusal to sign a peace deal on the region, Mr. Milosevic faces his most crucial test yet.

NATO's plans to strike Serbia represent the biggest military campaign for Europe since World War II. They also represent the first time since the breakup of Yugoslavia that Serbia - a land that has repeatedly sparked conflict elsewhere - would be under attack itself.

Milosevic faces difficult decisions. Will he resist to the end? Or will he give in and sign a peace agreement?

Analysts initially said NATO airstrikes could strengthen the regime, causing citizens to rally behind their leader. Now, they say, Milosevic risks losing all.

"If Milosevic takes this all the way, he will lose," says Milan St. Protic, a respected historian and analyst in Belgrade. "He will end up signing an agreement and getting nothing in return."

Yugoslav officials have remained defiant, saying they will defend their territory and not back down to NATO. "Units of the military and police are spreading all over the [Kosovo] region to avoid danger," Pavle Bulatovic, the Yugoslav minister of Defense, told a local radio station Tuesday night.

According to Natasa Kantic, executive director of the Humanitarian Law Center in Belgrade, the Yugoslav Army has begun a mobilization that is bigger than that of 1991-92, when the Serbs were at war in Croatia and Bosnia.

Yugoslav air-defense gunners and fighter pilots are expected to challenge a NATO assault, but they are considered vulnerable after dark because of inadequate night vision and night training, according to a Western official.

Airstrikes, which were ordered Tuesday by NATO Secretary-General Javier Solana, will be focused on the southern province of Kosovo. Fighting there between Serbian forces and the ethnic Albanian Kosovo Liberation Army (KLA) has escalated in the past week, forcing thousands of civilians to flee.

Western officials say Tomahawk missiles and bombs will first target air-defense sites and then other military installments throughout Serbia. The operation could reportedly take two to three weeks.

Roughly the size of Maryland, Kosovo has a 90 percent ethnic Albanian population, much of which wants independence. Last week, however, the ethnic Albanians signed a US- and European-sponsored proposal that would grant the region broad autonomy. The Serbs refused to sign, particularly objecting to an annex of the plan that calls for some 28,000 NATO troops to enter the region and police the agreement.

A possible, if not optimistic, outcome of airstrikes is that they will force Milosevic's government to sign the agreement.

"Anyone who signs an agreement after [airstrikes] - when they could have signed it before - could have big political problems," says Vladimir Goati, a political analyst in Belgrade.

Sonja Biserko, director of the Helsinki Committee for Human Rights in Belgrade, says the crisis is just beginning. "If Milosevic manages to control the situation, he will have to take control of everything in this society," she says. "If not, there will be a power struggle. I think he'll have trouble controlling the situation."

In Belgrade, independent media and opposition politicians were expecting a crackdown. Radio B-92, the strongest nongovernment news outlet, was shut down yesterday morning. Editor in chief Veran Matic was arrested, and later released, for "violating the law for peace and public order," says Marija Milosavljevic, a B-92 spokeswoman. Government officials cited technical reasons for closing the station.

"This is the most serious repression in Europe today. All democratic parts of society will be hostages in case of [NATO] aggression," Mr. Matic says.

In a surprising scene during an emergency session of the Serbian parliament Tuesday, Dragan Vesalinov, an opposition member, criticized the regime's position on Kosovo, and asked, "Where are the ministers and their sons" to fight the war? Mr. Vesalinov was cut off from the podium, and state television turned the camera away.

There were long food and gas lines around Belgrade, but the streets were relatively calm despite the declaration of a state of emergency. Children were ordered to go to school, and government workers were told to go to their jobs.

Many young men were in a state of panic as the Army mobilized. Some took back roads when moving through the city, hoping to avoid police and military officials.