PARIS. — Paris -- The world has yet to find an answer to the end of empire. No one regretted empires' going, but one appreciated the ruins they would leave behind.
Three great empires were destroyed by World War I, the Austro-Hungarian, Ottoman and Russian. Four more fell as a consequence of World War II. Most of the people who were subjects of those empires have probably lived worse lives since. Most have not even been free, despite their ''national liberation.''
The people of Balkan and Eastern Europe expected to be better off with the Hapsburgs and Ottomans gone. Whether they eventually will be so is not yet possible to say. Stalinism froze them in totalitarianism for a half-century.
The fundamental condition of this region is of nationalism without nations. Nowhere are national boundaries solidly established, universally recognized, coterminous with the geographical implantation of particular peoples: singular ethnic and language communities which consider themselves nations. Poland is perhaps the closest -- after vast killings and population transfers -- but there still are ethnic Germans in Poland and trouble about them. Hungary is itself coherent as a nation, but a large number of Hungarians live in Romania, and some in Yugoslavia.
Yugoslavia is breaking down because of its national contradictions. Woodrow Wilson's idea had been that ex-imperial Balkan and Eastern Europe, and the Middle East, could be parceled out into distinct nations. Millennia of westward migrations by the European peoples, however, had left the region in such a condition that was impossible: so eventually everything had to be approximation. The situation was worsened by romantic nationalisms that held a given nation to possess a redemptive mission to mankind and thus to be superior to others.
The United States and the European democracies have decided to oppose the current breakup of Yugoslavia and they have refused to give recognition to Slovenia's and Croatia's independence. This is a defensible policy which rests on the belief that to do otherwise would speed the disintegration not lTC only of Yugoslavia, but of Czechoslovakia and the Soviet Union, bringing unforeseeable and frightening risks.
In Yugoslavia, however, this Western policy encourages Serbia to use force to hold the two dissident nations inside the union. Hence it encourages violence, even though Washington and all the European governments are doing their best to make the Yugoslavs negotiate their crisis.
But Yugoslavia was an artificial grouping of nations from the start. Conflict was built into it because of the country's three hostile religions (Orthodox, Catholic, Muslim) and the ancient Serbo-Croatian rivalry that the new Yugoslavia internalized. As Paul Lendvai remarked in the journal International Affairs this spring, ''Yugoslavia is a country without Yugoslavs.'' Only 5 percent of the population so identified itself in the 1981 census. The rest identify themselves with the individual republics or as Muslims.
If the several Yugoslav nations will not coexist, then their separation has to be negotiated -- or adjudicated. It is a fact to remember that more Yugoslavs died during World War II fighting one another than fighting against the German and Italian occupying armies.
An important proposal has recently has been made by the former justice minister of France, Robert Badinter, now head of the French constitutional court. He argues that the international community should do its best to get not only these Yugoslav disputes of sovereignty and territory, but also the much wider range of conflicts developing in the East, into adjudication or formal conciliation in an international court.
He thinks there should be a new European court to handle conflicts that do not fall under the jurisdiction of the International Court of Justice at The Hague (disputes between sovereign states) or the Council of Europe's European Court on Human Rights, whose jurisdiction is recognized by more than 20 countries. Yugoslavia belongs to the council, and thereby has accepted ''the principles of the rule of law and of the enjoyment by all persons within (its) jurisdiction of human rights and fundamental freedoms.''
Mr. Badinter argues that the quality of a dispute changes when it is submitted to a tribunal, because to win in a court requires rational argument. Political negotiations, on the other hand, risk polarizing and politicizing disputes beyond what already is the case, provoking uncompromising nationalisms and feeding emotional commitment. Parties then look for allies and enlarge the dimensions of the quarrel.
Yugoslavia's present conflict cannot go to the Hague Court, because it is legally an internal matter. If Slovenia's and Croatia's sovereignty were recognized by the international community it could, in principle, and there could be an adjudication of frontiers. The rights of national minorities inside the new states -- one in four Serbs lives outside the Serb republic -- already are matters of Council of Europe competence.
Everyone recognizes that the international interest demands a peaceful settlement in Yugoslavia. The legal road is another one that could be followed in the search for a settlement. An urgent need exists for still stronger action by the United States and the West European governments to persuade Yugoslavs to reason rather than fight. It is, however, very late.
William Pfaff is a syndicated columnist.