Kosovo's declaration of independence has touched off an all-too-predictable spasm of violence and hostility in a region that emerged from devastating war scarcely a decade ago.
From setting fire to the U.S. Embassy in the Serbian capital of Belgrade to stone-throwing at NATO troops along the new unsteady border between Serbia and Kosovo, the anger of Serbs over the loss of a region they consider their cultural heartland is intense and dangerous.
And the United States, which backed Kosovo's separation from Serbia and was among the first countries to recognize it as a new nation, will receive the brunt of Serbian fury.
Far from stabilizing the region, as the Bush administration had forecast, the move by Kosovo has launched a period of volatile uncertainty.
Riots in Belgrade on Thursday night, which left one person dead, 150 injured and more than 200 arrested, were the largest outburst of anti-Western rage there since before the fall of dictator Slobodan Milosevic in October 2000.
Ljiljana Smajlovic, editor of Serbia's influential Politika daily newspaper, said the unrest represents a "tectonic shift" in Serbian public opinion, one that will carry far-reaching and unpredictable consequences.
Still, she and other Serbian analysts said in interviews Friday, an all-out war is unlikely to be among those consequences, for several reasons.
First, Serbia's military capacity today is far diminished from the days when a unified Yugoslavia fielded Europe's fourth-largest army. Many of its generals and commanders ended up at the international tribunal at The Hague, charged with war crimes related to the bloody campaigns they led to suppress the breakaway states of Croatia and Bosnia-Herzegovina.
And the ethnic Albanians who dominate Kosovo and who deployed a ferocious guerrilla army to fight for independence are on their best behavior while receiving favorable treatment from Western powers.
Second: There are 16,000 North Atlantic Treaty Organization troops deployed in Kosovo as well as a United Nations police force to give pause to any military challenges. The presence of international forces stands in marked contrast to Bosnia in 1992, for example, when civilians were left largely at the mercy of Serb paramilitaries, resulting in three years of bloodletting before NATO stepped in to help stop the killing.
Perhaps most important, Serbia today is a changed place. Milosevic, the architect of most of the warfare of the 1990s, is dead and buried. The last eight years have seen the rise of pro-Western, democratic leaders in Serbia who have fostered political change.
Many of them now feel betrayed.
They spent the last few years extolling the virtues of Western international law and justice, which included, they point out, the 1999 U.N. resolution that established self-rule for Kosovo, but as part of Serbia. They see as the epitome of hypocrisy that Washington went around the U.N., sidestepping the Security Council because of Russian opposition, to approve Kosovo independence.
"This is a total disaster for people who are pro-Western and pro-European," said editor Smajlovic. "This helps radicals who say it was never about democracy and right or wrong, but all along about taking away from Serbia, about humiliating the Serbs."
Many of the fiercest demonstrators torching buildings Thursday night and shouting, "Stop U.S. terror!" were young protesters who may have little memory of Milosevic but who came of age as NATO was bombing Belgrade in 1999 to force Serbia to end attacks in Kosovo.
Cedomir Antic, a historian with the Institute for Balkan Studies, noted that in elections this month, the ultranationalist Serbian Radical Party, though it lost narrowly, had managed to quadruple its vote over balloting in 2001, in part because of Kosovo.
"People are very frustrated," Antic said. "The Serbian government is very united on the issue of Kosovo, but very divided on where to go from here."
The division weakens the ruling democratic coalition and makes it possible the government will fall and the pro-Moscow Radical Party, whose president is also on trial for war crimes at The Hague, will take over.
What seems most likely, however, is that low-intensity skirmishes along the Serbia-Kosovo border will continue. On Friday, for the fifth consecutive day, Serbian protesters chanting, "Kosovo is ours!" hurled stones and bottles at U.N. police who were blocking a bridge in the volatile Kosovo town of Mitrovica that divides the Serbian north from the Albanian south. This week, similar gangs torched customs and police posts at other crossings between the two entities.
The debilitating divisions within the Serbian government were accentuated Friday in exchanges over who was to blame for Thursday night's violence, which came at the fringes of an otherwise peaceful demonstration. The "Kosovo is Serbia" rally was sponsored by the government and drew about 200,000 people.
President Boris Tadic, the most pro-Western of Serbia's top officials, who arranged to be away for the day, condemned the violence and said Friday the riots "must never happen again." Prime Minister Vojislav Kostunica, a nationalist, said the violence was wrong, but praised the demonstrators for showing the U.S. government that it was wrong too.
Though the two men are leaders in the ruling coalition, they are often at odds. Tadic wants Serbia to join the European Union regardless of the Kosovo decision, whereas Kostunica maintains that Serbia cannot be part of an EU that recognizes an independent Kosovo. Kostunica's championing of the Thursday rally was his attempt to allow Serbs to vent their anger, even though a small number took it to extremes.
Meanwhile, the EU, some of whose members have recognized Kosovo, warned Serbia on Friday that it was in danger of losing its chance to join the 27-nation bloc if such rioting persisted.
"These acts of violence lead nowhere and they cannot help anybody," EU foreign policy chief Javier Solana said. Initial talks aimed at prepping Serbia for membership would be frozen until peace was restored in Belgrade, he said.
Russia, Serbia's closest ally, threatened its own measures. If NATO exceeds its mandate in Kosovo, Russia's ambassador to NATO, Dmitri Rogozin, said, "then I think we will also begin operating under the assumption that in order to be respected, one needs to use force."
Another potential consequence of Kosovo's declaration is the unraveling of the region's delicate postwar balance, analysts say. Republika Srpska, the Serb portion of Bosnia-Herzegovina, threatened to follow Kosovo's lead and secede. That could destroy the U.S.-negotiated country that emerged from the 1992-95 war, which is divided into a Serb portion and a Muslim-Croat half.
And a sizable ethnic Albanian minority in Macedonia, another former Yugoslav republic, may find similar inspiration. There could be a tumultuous domino of secessions.
"I can't imagine anyone having the stomach for war now," Smajlovic said.
"But independence for Kosovo will not stabilize the region. It will stir things up. Nationalism is on the rise. It is not going to be a happier, more stable Balkans."