ONE of the most dangerous assignments for American soldiers in Bosnia is to supervise the removal of land mines from the front lines.
With an estimated 3 million to 6 million mines buried throughout Bosnia - along front lines that have been fluid during 3 1/2 years of ethnic war - few places are safe from the threat and there's plenty of work for American soldiers.
Just yesterday, a US combat vehicle ran over an antitank mine in central Bosnia. No one was hurt. But on Sunday, three British soldiers were killed when their vehicle ran over a mine in northwest Bosnia.
While performing the dangerous mission on the snow-encrusted ground, the soldiers' conversation often turns to how former neighbors became enemies - and how they might again be neighbors.
When the former combatants finish clearing a field, Americans test the area with mine-detection vehicles to confirm as near as possible that it is safe. ''We proof them, because they miss as many as they pick up,'' says one first sergeant.
The tale of one US Army platoon is typical, and provided insight - and a small history lesson - for the Americans into the complex war in Bosnia.
Under gray, snow-filled skies south of Brcko, in northeast Bosnia, a handful of American soldiers gathered in the middle of no man's land, along with Serb and Croat officers who were demining their front line. Greetings and handshakes more befitting long-separated friends than enemies were exchanged and work began.
The senior Croat officer, a major, produced a hand-drawn map of the minefield: Eight antitank mines lay buried under the frozen crust of snow, and 80 antipersonnel mines were scattered about nearby.
An elderly Croat soldier wearing a shallow World War I-style helmet wandered through the minefield 15 feet away, spreading salt to make the snow melt. Then Croats and Serbs together began stabbing the earth with long metal and fiberglass prods.
''I wasn't worried until they started prodding at my feet,'' says an American lieutenant, as he gently eases members of his team back a few strides.
Used to more stringent risk management, the peacekeepers stood amazed as one antitank mine after another was found, unearthed roughly with a trowel, and extracted with the help of a shovel. The mines - their plastic triggers protruding and slick with mud - were set nonchalantly aside.
Warming with their success, the Bosnian rivals brought out a bottle of plum brandy, produced a heavy loaf of bread, then carved a smoked ham. A rowdy lunch party began, and the men began telling war stories.
The Americans politely declined to partake of the liquor, but helped themselves to the meat. Soon joking among Serbs and Croats began in earnest, since they had known each other for a decade before the war. The officers even attended school together.
''When we fight, we fight, when we drink, we drink. '' a Serb officer says to the bemused Americans, explaining how old animosities are temporarily forgotten.
The trenches spun out along the snowy hills in all directions, silent except for the mewing of a stray marmalade cat. Not far away lay the wartime remnants of some homemade rifle rounds. The bullets had been pried away from the cartridges by some bored Bosnian soldier to make necklaces and to get the gunpowder to light fires.
''I feel sorry for all you guys being here,'' the Serb continues, as the GIs stamp the ground to keep warm. ''Only now do I realize this war was stupid; having all these young men standing around in trenches - for nothing.''
The Serb gave the Americans a small history lesson. It was politicians and their nationalist ethnic policies in 1991 who ''caused trouble between the people of Yugoslavia,'' he says. ''This was enough to start up the war.''
Overnight, all Serbs were branded with their extremist World War II title of ''Chetniks,'' he says. And all Croats were labeled with their fascist World War II name ''Ustashe.'' Only since a peace plan was negotiated by American diplomats for Serbs, Croats, and Muslims last November has there been peace.
While Serb and Croat deminers enjoy their lunch, the mutual atrocities are forgotten for a moment. ''The people who started the war are all gone now,'' the Serb adds, as Croats nod in agreement. ''Those who didn't start up the war, like us, are very nice.''
The map of the minefield is examined again. The Serbs took careful measurements when they put down mines - at least here, they say - but the Croats admit that their mines were laid here and there ''by carpenters and butchers.''
There is a sudden realization that beneath the lunch spot is the last mine. The Americans step back, with a gasp. Unworried, the Bosnians pick up the leftover rind of ham, the last scraps of bread, and two remaining oranges.
An old Serb soldier prods hard, digs some, then removes the round antitank mine from the mud with a sucking sound. There are enough explosives within its rusting case to lift the front end of a tank into the air.
Incredulous, the Americans look at each other, and one soldier speaks: ''We were standing on that, weren't we?''
A recognition about the limits of their mission - due principally to its one-year mandate - has come over some American troops. It coincides with a deeper understanding of Bosnia's warriors, that the enemies were once friends, but also that too much blood has been spilled to be easily forgotten. ''We can separate them, but we can't end their hatreds and anger,'' says the American first sergeant. ''You're not going to solve this [in] a year - it's going to take several generations for that to get worked out.''