IN HARM'S WAY

By GEORGE CHURCH MASSIMO CALABRESI/SARAJEVO, ANN M. SIMMONS/ HEIDELBERG, MARK THOMPSON/WASHINGTON AND BRUCE VAN VOORST/RAMSTEIN

IT SEEMS CERTAIN TO BE A WHITE Christmas; snow already covers the ground in Tuzla. But merry? The weather will be bitingly cold, the air filled with the stench of diesel fumes. Christmas dinner will be the T-rations detested by G.I.s; carols will be sung to the hum of noisy electric generators. And many of the soldiers setting up camps for the Bosnia peacekeeping operation will sleep in tents. Big ones with wooden floors, heat, fluorescent lights and flush toilets. But still tents.

At the Tuzla airfield, ground crews will have little time to gripe. The former Yugoslav airstrip for fighter planes has only one runway, on which the outlines of filled-in holes created by Serb shelling can still be plainly seen. No matter: plans call for a U.S. cargo plane to land there every 20 minutes all day and eventually through the night. And only three planes can be on the ground at any time. Can this ambitious schedule be met?

Speaking by telephone from a bullet-pocked control tower, Air Force Colonel Neal Patton, who has been in charge of installing runway lights and precision navigation equipment and otherwise getting the field ready, expresses confidence that it can handle the planned traffic. But he adds, with a laugh, "We're going to go to church to pray for better weather." Snow and low ceilings last week caused several flights either to be held on the ground at the Ramstein air base in Germany or to circle Tuzla fruitlessly and go back, unable to land. The miserable conditions do have their bright side, however. "There's nothing like sunshine for a good firefight," says Marine Lieut. General Anthony Zinni, "and this kind of weather discourages that."

In a sense, the frenzied activity at the air base will be misleading. Fewer than 1,000 of the 20,000 American peace enforcers will be encamped around Tuzla by Christmas. Many others will be aboard trains rumbling through Austria and the Czech Republic en route to jumping-off points in Hungary, from which they will advance 50-odd miles across Croatia into Bosnia and Herzegovina. Others will still be at bases in Germany, waiting their turn to board the trains; some may not leave until February. Army commanders strongly deny, however, that the buildup is slipping behind schedule. Says Colonel Mike Sullivan, chief spokesman for the U.S. Army, Europe: "Slow and gradual is exactly where we want to be. This is a very deliberate, precise process in vicious weather on a very unfavorable terrain, and we're very aware of that. We're not going to expose soldiers and their equipment to this until we're absolutely ready."

Just getting into Bosnia is no easy job. The bridges across the Sava River between Croatia and Bosnia have either been destroyed by artillery fire or are shaky. So Army engineers will build two "float" bridges of steel, aluminum and Styrofoam; by Christmas, the spans should be ready for tanks to rumble across them. It will be quite a sight. The bridges will settle six to eight inches under the weight of the tanks, and water will come up above their tracks. It will look as if the tanks are gliding across on top of the currents.

Once across the Sava, the troops will move to the Tuzla area along narrow, twisting roads blanketed in snow. Worse, the roads, winding along the bottoms of valleys, are highly vulnerable to snipers on the surrounding mountains. Advance troops will have to scour the hills to make sure their comrades can move along the roads in safety. Finally, in and around Tuzla, they will occupy a 500-mile-long border area designed to separate Serb from Muslim and Croat forces, setting up checkpoints and patrols to make sure nobody crosses without legitimate business.

It will not be the most dangerous assignment in Bosnia. That will probably fall to some 10,000 French troops in the Sarajevo sector. The peace agreement signed at the Elysee Palace in Paris on Dec. 14 virtually guarantees upheavals in the Bosnian capital. The pact consigns several Serb-populated suburbs to control by the Bosnian government. Rather than live under their hated enemies, Serbs are threatening to leave their homes in those suburbs and in the corridor to Gorazde in eastern Bosnia. Around Gorazde, some Serbs were stripping their homes of everything transportable--in at least one case literally including the kitchen sink--and setting out for the Serbs' Republika Srpska, newly recognized by the Paris deal. At night, convoys of army trucks trundle down the treacherous mountain slopes and haul out the insides of factories and military bases. The potential for new violence was underscored when two grenades and a mortar fired from the direction of Serb-held territory exploded in an unoccupied area of Sarajevo only minutes after the signing ceremony had flickered off TV screens. On the same day, Bosnian government forces shot at a French helicopter, and Croat soldiers clashed with mujahedin, Islamic volunteers fighting on the side of the Muslims, and killed six.

The signing ceremony was hardly a joyous affair. Bosnian President Alija Izetbegovic grumbled that "my government is taking part in this agreement without any enthusiasm but as someone taking a bitter yet useful potion or medication." He openly questioned whether the unified Bosnia foreseen in the treaty will "truly materialize or will it simply remain something on paper?" Croatian President Franjo Tudjman traced the roots of the crisis in Bosnia back more than 15 centuries to "the breakup between the Western Roman Empire and the Eastern Roman Empire," obviously implying that the wounds cannot be healed quickly. Bill Clinton, who presided in fact if not in name, was far more upbeat. He predicted that "soon the Bosnian people will see for themselves the awesome potential of people to turn from conflict to cooperation."

It could be argued that despite the treaty, there is still no peace to keep in Bosnia. That was the problem the United Nations peacekeepers faced for years, and the dangers of enforcing a peace among still hostile peoples hardly needs to be impressed on the French or British troops who will implement the treaty. Both countries participated in the old U.N. force, and many of their soldiers will now simply be exchanging their U.N. Blue Helmets for those of their national uniforms. The big difference: as lightly armed U.N. troops, they operated under highly restricted rules of engagement and paid a terrible price. The U.N. peacekeeping force in Bosnia suffered more than 100 fatalities, including 56 French and 18 British soldiers.

As peace enforcers serving under NATO command, the French, British, American and other members of the 60,000-strong international implementation force--32 countries in all are definitely participating in Operation Joint Endeavor--will carry heavy weapons and be authorized to shoot not only if they come under fire but even if they are just threatened. American G.I.s specifically can fire if anyone points a gun at them in a menacing fashion. And the order to fire need not come down any chain of command. It can be given by a sergeant on the spot.

Even so, Bosnia is a dangerous assignment. Atop the worry list for everyone, from private in the field to general in the Pentagon, is land mines. Overall, experts think the former Yugoslavia has been sown with anywhere from 2 million to 6 million mines. The American sector is known to contain three big minefields plus heaven knows how many mines planted individually and in small clusters. Tore Skedsmo, a U.N. mine expert, says all sides in the Bosnian war--Serbs, Croats and Muslims--"were laying mines like mad" right up until Nov. 21, when the basic peace agreement was initialed near Dayton, Ohio.

Signs of some suspected mine clusters can be spotted from the air by Apache helicopters. Explosive-sniffing dogs and tank-mounted rakes and rollers can help clear a path through a minefield, but many mines will have to be dug out by hand. Says General John Shalikashvili, Chairman of the U.S. Joint Chiefs of Staff: "That's why an awful lot of soldiers have been spending a lot of time on their hands and knees learning the old-fashioned way" during training exercises in Germany. The difficulties of clearing mines are immensely multiplied if roads and fields are covered by deep snow.

The mujahedin are another major concern. An estimated 2,500 to 4,000 of them--1,000 in the American sector-to-be--have been fighting in Bosnia on the side of their fellow Muslims but under the effective control of no one. Many are radical fundamentalists from such countries as Iran, Afghanistan and Syria who view all Westerners, especially Americans, with suspicion and hostility. Under terms of the peace treaty, all unauthorized foreign forces, including the mujahedin, are to get out of Bosnia within 30 days. Undoubtedly some will. But Pentagon officials are worried that others will go underground. U.S. officials point out that the 20,000 American troops will be spread out along 500 miles of the separation zone, or 40 to a mile, leaving few big concentrations to serve as targets for a car bomb. Says a senior officer: "We've learned a lot since Beirut," where 241 servicemen died in a suicide bombing of a Marine barracks in 1983. Even so, such an attack is cause for concern--certainly fuel oil and fertilizer, the ingredients for a simple but powerful bomb, are easily available in Bosnia.

To reassure the U.S. public that the G.I.s are not being sent on an endless and escalating mission, General Shalikashvili makes a point of ticking off all the things the troops will not do. "The implementation force will not be responsible for the conduct of humanitarian operations," he says. "It will not be a police force. It will not conduct nation building. It will not be a disarmament force and chase after people to collect weapons and whatnot. And it will not be responsible for the movement of refugees." In other words, this time there will be no "mission creep," Pentagonese for the gradual expansion of tasks, which turned the Somalia intervention from an initial success to an eventual debacle.

No one is minimizing the dangers of carrying out even the limited military tasks of the mission, however. To blunt those dangers, American planners are relying heavily on surveillance equipment and training. Two J-STARS (for Joint Surveillance Target Attack Radar System) planes will keep watch over Bosnia while flying eight miles above either the Adriatic Sea or Hungary. Their computers can distinguish personnel and troop movements, even though they cannot, unaided, tell a tank from a car. According to plans, the locations of all concentrations of Balkan armor will be entered into the computer memory banks so the j-stars can track movements out of those areas. Apache helicopters will keep constant watch near U.S. troop units when the fog so common above Bosnian snowbanks lifts enough to permit the choppers to fly. Anti-sniper teams, equipped with heat-detection units and long-range rifles, will be able to defeat any gunman waiting to ambush approaching soldiers.

The nature of the NATO mission--policing long, snakelike "zones of separation" between the warring factions--means that troops will never be far out of mortar and artillery range. Any Balkan soldier who chooses to will easily be able to fire a couple of shells at them. After doing so, however, he will have to move quickly to avoid being hit by NATO's sophisticated counter-artillery fire. A senior Army planner says, "We would expect to return artillery fire at the location where it's coming from almost before the round hits the ground."

Training exercises in Germany, held in bitter cold, have covered almost every conceivable situation: ambushes, sniper fire, 200 people identifying themselves as refugees trying to cross U.S. lines and begging for food and water. Be polite and non-confrontational but don't feed them, the troops are told. Some of the exercises have been carried out amid ear-shattering recorded noises of artillery fire. In land-mine-awareness lessons, troops are instructed never to take a short cut when navigating unfamiliar terrain and never to try to defuse a mine by themselves. Instead, they are told to mark it with a red bicycle flag and white tape so that, in the words of Sergeant First Class Charles Bradley, as he conducted an outdoor course in Schwetzingen, Germany, "even the dumbest guys in your unit can identify it."

Much training involves negotiating with local citizens who may have important information but may be suspicious and speak little if any English. Pick "the trash talkers in your group" to negotiate, Bradley advises. "These are the guys who can establish a rapport." As an object lesson, some troops being trained by Bradley performed a sort of playlet. A scruffy-looking young man in jeans and a hooded sweat top rushed out of bushes into the path of a convoy of G.I.s. He waved his arms wildly, sputtering in an incomprehensible language but making clear with gestures that he was trying to block the troops from proceeding any further. One of the soldiers was chosen to try to get some information about surface-laid land mines on the path ahead. The young man, however, was hostile and refused to believe that these were U.S. soldiers. "No American, no!" he shouted. But one of the soldiers showed his U.S. Army ID card; another gave the wild man some water. The civilian--actually, of course, an American soldier playacting with relish--then turned friendly and trampled on the mines to show they were fakes, strewn about to discourage the troops from going that way.

All the careful planning has not allayed the doubts and fears of Americans back home. But some U.S. allies in the implementation force seem outright ebullient about the turn the situation in Bosnia has taken. The discussion in the British Parliament when Tory Defense Secretary Michael Portillo presented the deployment plan barely deserved the name debate. Labour M.P. David Clark said, "I am more than delighted to assure [Portillo] that he has the full support of the House." In the U.S., however, the Senate only grudgingly passed a resolution supporting the troops but not necessarily their mission. The House did vote against the Administration's policy, though it failed to pass a motion to cut off funding.

Some G.I.s too are dubious about the Bosnia mission. On computerized networks, they have called it Operation Just Because. (George Bush's 1989 intervention in Panama was called Operation Just Cause.) A sergeant at the U.S. Army base in Baumholder, Germany, was jailed for threatening to kill President Clinton when he visited early in December.

The great majority of U.S. soldiers, however, regard their mission with cool professionalism: this is their job, they have trained for it, they will do it. They are, of course, well aware of the dangers. Among other things, they have been advised to make out wills. Those hitting the road to Bosnia early were not thrilled, either, to say goodbye to their families at German bases just before Christmas. Still, none could be found who would disparage the enterprise to reporters. "I'm excited to go," said Captain Gregg Ortiz, 33, of the Army's 72nd Signal Battalion, based in Mannheim, as he left for Zagreb. "I feel I've been gearing up for this. I've been talking to my oldest daughter [Christine, 7; another daughter, Corinne, is two], saying, 'Honey, it's part of my job. We are going to keep the peace.'"

Less enthusiastic but perhaps more typical, Private First Class Michael Ftacnik, 26, who was scheduled to fly into Tuzla to help set up a satellite-communications dish, allowed that his mother "doesn't like the idea" of his deployment. And he knows that "of course there will be casualties." But he says, "If we can help stop the killing, then it's fine with me." --Reported by Massimo Calabresi/Sarajevo, Ann M. Simmons/ Heidelberg, Mark Thompson/Washington and Bruce van Voorst/Ramstein