Independence fighters from the Kosovo Liberation Army appear to be gradually seizing control of Serbia's southern province.
The ethnic Albanian KLA has taken main roads, farming villages, and even one town in Kosovo, of which they now control about 40 percent.
The KLA has also won the ear of the West. Richard Holbrooke, chief American negotiator in the Balkans, said yesterday that the US had opened a channel to leaders of ethnic Albanian rebels - and said they deserve a seat at the peace table if they control their fighters on the ground.
But with each KLA victory, the prospects for peace in Kosovo diminish, observers say. While the under-armed guerrillas are growing in numbers and confidence, the uninspired Serbian forces have only their heavy weaponry to fall back upon.
And KLA gains on the ground have been mounting. Last week, guerrillas captured a coal mine that feeds an electricity plant for the provincial capital of Pristina, just 15 miles away.
"We could be looking at a guerrilla war that lasts for years," says an analyst who has traveled through Kosovo's "war zones."
Mr. Holbrooke, who orchestrated the 1995 Dayton accords ending the war in Bosnia, last week shuttled back and forth between Belgrade and Pristina to try to jump-start talks between Yugoslav President Slobodan Milosevic and ethnic Albanian leaders.
"I wouldn't want to get your expectations up that we're going to have any breakthroughs, because the situation is quite difficult," he said in a television interview last week.
Yesterday, he insisted that contacts with the KLA did not mean the US was distancing itself from Ibrahim Rugova, the US-backed pacifist who was elected de facto president of Kosovo in underground elections in 1992.
With the KLA advancing almost daily, diplomats are struggling to come up with demands to impose on Mr. Milosevic, whose forces have killed scores of civilians and sent as many as 70,000 ethnic Albanians fleeing.
Diplomats have asked Milosevic to withdraw his special military forces, but the Russians have argued that a withdrawal would likely result in massive gains by the KLA. If anything, Milosevic appears to be bolstering his forces in the region.
Also, the international community does not support outright independence for Kosovo, which is the singular demand of the KLA.
Meanwhile, the KLA remains enigmatic, with neither clear leadership nor a proven ability to integrate military and civilian life. While several prominent ethnic Albanian leaders try to form the organization's political wing, they fight on.
"I am ready to die," says one young KLA soldier in the western village of Propocane. "We all are."
Mr. Rugova seems to have little control over the KLA. A new, more radical political coalition led by two former political prisoners, Adem Demaci and Hidajet Hiseni, is more likely to represent the guerrillas.
The prospects of NATO intervention are also laden with question marks. Air strikes against Serbian positions could be seen as tacit support for the KLA.
And deployment of ground troops is nearly impossible without a peace agreement to enforce.
It is also possible that fighting could spread to neighboring Albania or Macedonia, both of which have restive elements. Macedonian officials last week accused Yugoslav fighter jets of violating their air space.
On the ground in Kosovo, where Albanians are 90 percent of the 2 million population, front lines are constantly moving, with new KLA posts springing up everywhere.
In the western village of Krusec, which was "liberated" on May 29, every able-bodied ethnic Albanian has taken a gun, says the local KLA commander, who served 13 years in the Yugoslav Army.
"We are defending our village and we have the help of everyone who wants independence," the commander says. "We are all together."
Just a few miles away, on the main road linking the cities of Decani and Pec, the Serb forces patrol, but seem to have little knowledge of what lies behind the tree line.
"Are there terrorists back there?" they ask.