Two days ago Bosnia's Muslim-Croat federation took control of Grbavica, the last of five Serb-held Sarajevo suburbs designated for transfer under the Dayton accord. About 60,000 Serbs lived in these suburbs during the 1992-95 war; only about 10,000 remain.
The rest, bullied by Bosnian Serb authorities into abandoning their homes, or acting on their own nationalistic impulses, have sacked and burned their neighbourhoods, dismantling everything from washing machines to electric light fittings and digging up their dead for reburial in Serb territory.
For their part, the Muslim authorities have done little to encourage the Serbs to stay, turning a blind eye to marauding, vengeful Muslim gangs.
Sarajevo, once a beacon of Balkan multi-culturalism, has earned the dubious distinction of becoming the setting for a final, frenzied burst of "ethnic cleansing" - the separation by violence of one nationality from another. Across Bosnia, mixed communities are mostly a thing of the past.
The Serb Republic, allocated 49 per cent of Bosnia's territory under Dayton, is all but purged of Muslims and Croats. In Banja Luka, its biggest city, the mosques have long since been blown up. Hardly any Muslims remain in the Drina valley in eastern Bosnia, where they were the largest nationality.
The Muslim-Croat federation, covering the other 51 per cent of Bosnia, exists on paper but not in the hearts of the two peoples or in the political calculations of their leaders. The Croats of western Herzegovina persist in defending their separatist mini-state, Herzeg-Bosnia, in the confident expectation that it will one day unite with Croatia proper.
The Muslims, once the most committed to multi-national co-existence, find themselves boxed into a tight space in central Bosnia focused on Sarajevo. While some Muslim politicians, such as the former prime minister Haris Silajdzic, hope to recreate a multi-national Bosnia, the leadership in Sarajevo under President Alija Izetbegovic prefers to emulate the Serbs and Croats, making nationalism the centrepiece of its programme.
The partition of Bosnia reflects the enormous population movements of the war: more than half the republic's 4.4 million people fled or were driven from their homes. Many thousands became refugees abroad. Inside Bosnia mixed communities broke down and Muslims, Serbs and Croats began to resettle, often reluctantly at first, in nationally exclusive areas. There seems little hope of coaxing them back together.
Is the lesson of Bosnia that multi-ethnic states are doomed to fail in Europe? Are population transfers, however offensive to the liberal Western conscience, a necessary evil to ensure stability?
Such questions do not touch on distant issues of principle but are relevant to western Europe in a direct way. European ethnic rivalries that turn violent can lead to Western military intervention as well as to large influxes of refugees.
Clearly, if a state's dominant nationality and its minorities are not in conflict, then there is no need to move out the minorities. No one would suggest transferring Finland's Swedish minority to Sweden or Belgium's German minority to Germany.
But this is largely because the Finnish and Belgian states fully protect the rights of the Swedish and German communities. In law-based democracies with strong traditions of civil society and political tolerance, the question of population transfers does not arise.
In eastern Europe and the former Soviet Union, the picture is less clear. The region contains a number of new states, or states that recently regained independence, which lack the political maturity to treat minorities fairly.
There is a history, too, of vast population upheavals in the region. The expulsion of millions of Germans from the former Czechoslovakia and Poland after the Second World War was a brutal act, yet it probably contributed to stability in central Europe. Czechoslovakia split into Czech and Slovak states in 1993. The divorce might have been far more complicated if the new-born Czech Republic, a state of 10 million people, had contained 3 million Germans settled in strategic border areas.
In Poland, a sizeable German population remained in western areas after 1945 and, upon the fall of Communism in 1989, demanded long-denied political and cultural recognition. Poland's new leaders, who emerged from the Solidarity opposition, wisely guaranteed their rights, defusing an issue that could have stoked dangerous passions in Germans and Poles.
Poland represents an isolated success story in post-Communist Europe. Elsewhere, a country's dominant nationality more often than not views minorities as a threat.
The substantial ethnic Hungarian communities of Romania, Serbia and Slovakia are a case in point. In all three countries, especially Romania, state- sponsored nationalism is a stronger force than the spirit of civic co- existence that might breed respect for ethnic Hungarians' equality under the law.
Tensions have not developed to the point of armed conflict. The prospect of entry into the European Union and Nato provides Hungary, Romania and Slovakia with an incentive to avoid violence and reach a compromise. However, the longer the West delays admitting these countries, the higher is the risk of serious trouble arising over the Hungarian minorities.
Bosnia's de facto partition sets a bad precedent for countries in south- eastern Europe, where democratic institutions are fragile and mutually hostile nationalisms clash. Discontent runs deep in the ethnic Albanian communities of Kosovo, Serbia's southern province, and in the Former Yugoslav Republic of Macedonia. It is not hard to imagine the tensions boiling over.
This could result in the forced expulsion or flight of most Albanians from Kosovo and Macedonia into Albania. Large-scale population movements have already started in Kosovo: about 250,000 of the province's 1.7 million Albanians have left since 1990. The great majority have ended up not in Albania but in the United States and Germany.
The southern Balkans might be more stable with an Albanian state that included most ethnic Albanians, rather than large numbers being spread over at least three different countries. As long as basic standards of democracy and respect for minority rights are inadequate in Kosovo, the Albanian problem will remain a timebomb.
Although Greek-Turkish relations are rarely free of tension, it is sometimes forgotten that the two countries have not gone to war for more than 70 years. One reason is that the 1923 Treaty of Lausanne provided for the compulsory exchange of Turkish Muslims and Greek Christians between Greece and Turkey, greatly simplifying the ethnic make-up of the two states.
Population transfers in the twentieth century have generally been either an accompaniment to war, as in Bosnia, or a feature of subsequent peace arrangements, as after 1945 in central and eastern Europe. The human cost has been terrible, but sometimes the long-term effect has been beneficial.
Ideally, ethnic minorities in turbulent parts of Europe such as the Balkans would enjoy complete security in political systems framed by tolerance and respect for the law. The harsh truth is that such conditions do not obtain in much of the region.
Indeed, in some areas the prospects for inter-ethnic violence are rather greater than those for the consolidation of democracy. They are likely to remain so as long as strident nationalism remains the stock in trade of leading political parties.
In such circumstances, if war does break out on the scale seen in Bosnia, it may be necessary to accept as a hard reality the forced transfers of population provoked by the fighting. In western European eyes, the separation of nationalities is not a noble ideal, but in eastern eyes it can have the virtue of offering a respite from lengthy wars.
Bosnia under the Dayton agreement
Capital: Sarajevo: name derived from Saraj Ovasi, literally "palace in the fields". The city's population is around 470,000. Pre-1991, a mixture of Serb, Croat and mainly Muslim. After 1991, the centre became a government stronghold under siege from Serb suburbs.
History of a city
AD9: Romans establish rest centre at Ilidza close to what is now Sarajevo.
1415: First mention of Sarajevo as Vrh Bosna, a Slav castle.
1428: Vrh Bosna falls to the Turks, an invasion that turns city into a trading centre and stronghold of Muslim culture, making it one of largest, richest and most beautiful cities of the Turkish-ruled Balkans.
1451-1553: Sarajevo ruled by native Slavs who have converted to Islam.
1550: Jews fleeing from Spain begin to settle in the city.
16th and 17th centuries: A period of prosperity is followed by a series of floods, fires and plagues that savage Sarajevo's population.
1850: Sarajevo becomes the administrative centre of the declining Ottoman Empire.
1875: After more than 400 years of occupation, Turks are ousted from Sarajevo by the Austro-Hungarian Empire.
1878: The Treaty of Berlin assigns Bosnia to Austria. Building boom starts. City becomes known for its intelligentsia. National independence becomes hotly debated.
1908: The Austro-Hungarian Empire formally annexes Bosnia and Herzegovina.
June 1914: Gavrilo Princip assassinates Austrian Archduke Franz Ferdinand I, triggering First World War.
November 1918: Diet of Sarajevo proclaims union within Yugoslavia.
1945: Sarajevo becomes capital of Bosnia, one of six republics in the Communist Yugoslav Federation. It had escaped two World Wars relatively unscathed.
1946: Sarajevo University established.
1984: Winter Olympics
Feb/Mar 1992: Yugoslavia breaks up after a Serb-boycotted referendum in which Muslims and Croats vote for independence.
5 April 1992: Bosnia's parliament declares independence. The city gets its first taste of battle for 300 years. Mass peace demonstration fired upon by snipers. Scores of civilians killed or wounded. The following day, Serb-dominated Yugoslav National Army units began to shell Sarajevo. Three-year siege begins.
18 Feb 1994: First marketplace massacre: 68 killed by a mortar fired from outside the city.
29 Aug 1995: Second marketplace massacre. 37 die in the same marketplace, victims of another shell.
Dec 1995: War ends
Mar 1996: City reunited as the transfer of Serb suburbs to Muslim/Croat control completed.
Research: Anna Davies
and Ben Summers