Different–but still deadly dangerous. The hard reality confronting U.S. troops bound for patrol in the bleak city of Tuzla–headquarters for the American sector–is that their mission is fraught with risk. Narrow, torn-up roads will be hellish to traverse, particularly in the ice and subzero temperatures of a Balkan winter. The mountainous sector the United States will oversee is also laden with mines. Likely American bases are within easy range of Serb artillery. And last week Pentagon officials revealed their concern about knots of non-Bosnian Muslims–“hard-core terrorists,” one official called them–who went to the war zone to aid the Muslims, and now linger to the south of Tuzla. Many are said to be from Mideast countries already hostile to the United States. Others could bear a grudge against America for its failure to intervene sooner.

American officials know there will be casualties, and are concerned that the death toll could sap whatever political will exists at home. They call it the “mother test”: how many body bags can the United States endure before domestic support completely evaporates? “Do we worry about it?” asks Gen. John B. Sylvester, one of the Pentagon’s chief Bosnia planners. “Sure. It’s always in the back of your head.” America’s allies are also fretting about U.S. casual-ties–and the body count’s impact on the alliance’s cohesion. Sylvester acknowledges that there is a feeling among the allies that “the U.S. has a weak stomach” when it comes to dead soldiers.

That may well be the reason the Americans ended up in Tuzla. It will hardly be pleasant–the town is oppressively gray, almost constantly shrouded in smog and virtually lifeless at night, thanks to a 10 p.m. curfew. But Tuzla may well turn out to be less volatile than the turf the British and the French will patrol. American troops do not need to oversee any significant transfers of land from the Serbs to the Bosnian government. And in an arrangement that Americans may come to appreciate deeply, Russian troops will primarily be responsible for the notorious Posavina Corridor north of Tuzla. The Serbs want that land as a bridge to Serbia in the east, and at Dayton the Bosnians adamantly refused. The corridor was bitterly fought over, and in Ohio neither side could agree on its fate. NATO hopes even renegade Serbs will be unlikely to turn their guns on Russians, whose government tilted toward Belgrade during the war.

Washington’s traditional allies, the British and the French, also plainly have tougher assignments than do U.S. troops–a fact that, in addition to the possibility that America will arm the Bosnians, is adding to the strain on the NATO alliance. The British will effectively oversee the northwestern patch of the country near Croatia. There are towns there the Croats took during an offensive in October, and they are loath to give them up, as the peace treaty compels them to do. Last week angry Croat soldiers were reportedly burning buildings in the two towns they are expected to give up–Mrkonjic Grad and Sipovo.

The next Beirut? More difficult still is Sarajevo, which could erupt into Beirut-like chaos. Demonstrations and random violence will no doubt come. In the suburbs, about 70,000 Serbs will probably leave when the Dayton terms are implemented because they do not want to live under Bosnian control. While some are already packing quietly, many vow resistance. The French have nm the United Nations’ Sarajevo blue-helmet operation, and now inherit the same task under NATO. And the French have made it plain they are not pleased. Jean-Rene Bachelet, who will command the French NATO troops, suggested that the United States had struck a deal that left France in charge of a perilous Sarajevo. Bachelet claimed he now had to enforce a plan “Paris never agreed to. In Dayton, General de Gaulle would have no doubt slammed the door.”

Bachelet, for now, may have a point. At the outset, the U.S. military–the force Defense Secretary William Perry called “the meanest dog on the block” – may face the least daunting challenges. Given America’s supposedly weak stomach, that may have been the better part of valor. In the end, it may not matter much. During the war, there were no safe havens in Bosnia. There may not be any in peace, either.