PEOPLE on the Serb-held side of Sarajevo first started noticing the tram a few months ago. Just across the front line they saw the traditional orange cars of Sarajevo's streetcar system working again, but one of the cars was painted bright yellow.
The yellow car, Serbs say, is the only one they will be allowed to ride in when all of the city is turned over to the Muslim-led Bosnian government. It's unclear how the rumor started, but it spread to the point where local Serbs began asking Western correspondents who live here if it is true.
With 20,000 American troops on their way to Bosnia after the signing of the US-brokered peace accord in Paris yesterday, the biggest impediment to peace appears to be rumors and innuendo. The weeks that have passed since the agreement was initialed have produced little of the intransigence and backtracking that observers feared.
Peace, for the short term at least, has enveloped the majority of Bosnia's population.
In an apparent protest of the peace signing yesterday, four shells were fired into the capital. But UN officials say fears of defiant Serbs in Sarajevo reigniting the fighting here, or of Bosnian Serb terrorist cells springing up, appear overblown. Sarajevo residents are cautiously optimistic that the war is over for now. UN officials predict the peace will hold here for at least the next year because three ethnically pure states have been formed, and all the sides are exhausted.
The failure of efforts by Bosnian Serb leaders Radovan Karadzic and Gen. Ratko Mladic to scuttle the peace deal, along with their release of two French pilots this week, indicates that Serbian President Slobodan Milosevic is in control in Bosnian Serb territory. Mr. Milosevic, who is eager to end the war and revitalize Serbia's devastated economy and international image, seems unwilling to tolerate any attempts by Serbs to hold on to the Serb-held land around Sarajevo and in Eastern Slavonia, which he gave away to Croatia in Dayton, Ohio.
''All of the Serbs are going to leave Sarajevo, and all of the Serbs are going to leave Eastern Slavonia,'' says a senior United Nations official based in Zagreb, Croatia. ''Milosevic told us last week he expects that and is ready for it.''
Serbs who have been loudly protesting turning over their neighborhoods to the Muslim-led government around Sarajevo will probably flee, according to UN officials. There will be no house-to-house fighting, but the Serb departure will be ugly.
Bosnian Serb authorities around Sarajevo have requested UN aid in digging up thousands of coffins in Serb neighborhoods slated to be turned over to the Muslim-led government. Serb families planning to leave the city say they will take their dead with them. Dramatic processions involving coffins, house burnings, and protests are expected.
Since the pact was initialed in Dayton on Nov. 21, it has held well, according to UN officials. There have been no sniping incidents on either side of the front line, and UN officials say exhaustion on both sides after nearly four years of brutal war will probably overwhelm any desire for revenge for now.
''Look at the civilians here in Sarajevo,'' says one UN military official. ''They've probably seen more fighting than some of the soldiers in the Army. The Serbs aren't willing to restart the entire war over those neighborhoods.''
Overcoming rumors like the one about segregated tram cars will have to occur if the peace is to hold. But Bosnian President Alija Izetbegovic has done little to improve the situation and has heightened Serbs' fears of random retribution against them, according to Western officials. ''In meetings last week, when the idea of being magnanimous in victory was brought up,'' says the senior UN official, ''Izetbegovic [publicly] says everyone except people who took up arms against the government is welcome - which means every father and son in every Serb family on the other side.''
Many Bosnian Serbs have lived in total isolation, interpreting the world through the only information source they have - nationalist Bosnian Serb leader Karadzic's television station. According to press reports, children in Serb-held Sarajevo suburbs are drawing pictures of NATO troops executing Bosnian Serbs.
What will happen in elections planned to be held six to nine months from now, and what happens in a year when NATO leaves, is unclear. Wrangling among political parties in Bosnia has already begun over who will control the billions of dollars in reconstruction money bound for Bosnia. As in other former communist countries, whoever has jobs to offer will have political power in Bosnia.
Tensions and instability will be heightened, observers warn, especially if President Izetbegovic's party and Bosnian Serb leader Karadzic's party continue to dominate political life here. And if the Muslim-led Bosnian Army becomes too strong, it may be tempted to take all Serb territory after NATO leaves.
Officials say plans to allow refugees to return to territories from which they were expelled are unrealistic. Extremists on all sides, especially the Bosnian Serb leadership, have succeeded in ''ethnically cleansing'' once-mixed Bosnian areas.
Three clear Croat, Muslim, and Serb spheres have emerged from the war, and that is unlikely to change for years. ''If the goal in the beginning was ethnic purity,'' says one UN military official. ''Then they've done it.''