'Hold Your Line! Hold Your Fire!'

It started with Serbs spitting at the Americans. Soldiers of the 82d Airborne Division were emerging from a building in Mitrovica, Kosovo, that they'd just searched for weapons. A crowd gathered. "Come on, shoot me, you cowards," one Serbian man shouted, baring his chest. "You can't bomb us now," another sneered. Capt. Mark Pratt ordered the 132 men of his Bravo Company to stand shoulder to shoulder. "Hold your line, Joes," he and his noncoms shouted. That was easy enough. "And hold your fire!" That was harder.

"All we could do is stand there and take it," said Specialist David Arsen, 24, of Tacoma, Wash.--even when a snowball barrage gave way to trash, rocks and paving stones. A brick hit machine-gunner Michael Shane Price, 29, in the face and knocked him, dazed, out of his turret. He was one of two men treated by medics; many others had cuts and bruises.

"It could have gone either way," said Pratt. And that's what made Mitrovica so frightening. A year after the start of the war in Kosovo, the province remains a place that is at best in a state of cold peace. Communal relations between Albanians and those few Serbs who remain are murderous. Serb dictator Slobodan Milosevic, still in Belgrade, is willing and able to foment trouble in Kosovo. NATO's commitment to the peacekeeping mission is halfhearted. There are meant to be 49,000 troops in Kosovo; at present just 37,000 are there, and when NATO Supreme Commander Gen. Wesley Clark called for urgent reinforcements last week, NATO's North Atlantic Council turned him down. It's easy to see how a spark could ignite a real fire, how a humanitarian intervention could turn into a military disaster.

For the Americans, whose Kosovo Protection Force (KFOR) contingent of 5,500 is the largest of any nation, the workload is daunting. U.S. troops mount an average of more than 300 patrols a day--the bulk of them on foot, and many of them 12 to 14 hours long. They don't normally work in volatile Mitrovica, and KFOR quickly pulled the 82d out of there last week. But even in their own sector, the southeast of Kosovo, it's hardly quiet. Consider Novo Brdo, where the 63d Armored keeps the peace among snow-covered mountain villages: in the last two weeks an elderly Serb was murdered, a village of 15 families was robbed and chased away and an apartment building was torched next to the American base. ''It's been real slow lately," says the company's First Sgt. Ernest Roth, a veteran of Somalia and Bosnia. "Right now Kosovo is off the radar screen back home, but they kill 15 or 20 Americans and it could change everything."

No one rules that out. So far only one U.S. soldier has been killed in hostile action, an American liaison officer blown up by a remote-controlled land mine in the Russian sector last December. Some of the U.S. soldiers think the way to deter further attacks is to get tough with all the locals. The U.S. Army is investigating complaints that some 82d Airborne troopers were routinely roughing up Albanians in Vitina, where a soldier from the same unit has been charged with the sex murder of an 11-year-old girl. At Gnjilane, many soldiers talk about how to handle curfew violators: "Beat them up a little, and lock them up," as one Pfc. put it.

"If we left, I'm convinced the Serbs would all be dead in a week," says Capt. Brian Byers. "They're all [living] just a hand grenade's toss from one another." In fact, grenades cost only about $7.50 apiece in Kosovo. Easier than a gun to hide, they've become the terror weapon of choice, tossed into Serb homes almost nightly in Gnjilane.

Usually KFOR soldiers don't catch the terrorists. When they do, they're quickly released. Kosovo still doesn't have a judicial system, and its few prisons are overcrowded. Even an Albanian curfew breaker who tried to pull a pistol on American soldiers was back on the street last week.

American soldiers find some consolation counting the days until they can get out themselves. At the Bravo Company command hut in Camp Monteith near Gnjilane last Thursday, the situation board toted up the scheduled R&Rs (none), patrols (10) and, up top where no one can miss it, the days left in their tour: "116."

Other Americans will replace them. Clinton administration officials don't expect a resolution of the Serbian province's status for 10 to 20 years. They say U.S. pullouts won't be possible unless Milosevic falls--if he ever does. Most peacekeeping operations assume both sides have agreed on a peace plan. In Kosovo, the Serbs have not, and the Albanians are at odds with each other. KFOR must post 24-hour sentries at the homes of Serbs in Albanian neighborhoods, escort their children to school and even take their parents out shopping--when they're not busting them for trying to kill one another. "The U.S. Army, your soldier on the beat," cracks paratrooper Jim Keaton of Kansas, who was hit by a Serb-thrown rock last week. Like many others who have stepped in to break up someone else's fight, he learned that neither side is likely to be grateful.