GENEVA - The slaughter of 68 people at a crowded market in Sarajevo on Saturday brutally demonstrates how ineffectual Western leaders and the United Nations have been in stopping the genocide in Bosnia.

Less noticed is the discreet gutting of the one opportunity for justice - however inadequate - that the international community had promised to the citizens of that abused country.

The teeth are being pulled from the International War Crimes Tribunal, set up by the UN Security Council with fanfare last year. The UN WarCrimes Commission, which is charged with assembling evidence, will soon be disbanded.

This is being done by the very statesmen who hailed the tribunal - at least publicly - as the means of ensuring that however unfavorable a peace settlement would be to the Bosnians, they could at least see justice done to the perpetrators of mass rape, murder and torture.

For people who have lost family. homes, communities and country, the prospect of protracted international legal proceedings against the Serbian and Croatian leaders Slobodan Milosevic, Franjo Tudjman, Radovan Karadzic and their lieutenants might seem cold comfort at best.

Yet, as the Nuremberg trials demonstrated, holding a vicious regime to account is an important act of renewal for both sides. Now that opportunity may be lost.

The UN secretary-general, Butros Butros Ghali,has indicated that he expects the War Crimes Commission to wrap up its work by April.

This abrupt closing of the investigation before the tribunal is properly up and running is already having consequences on the ground. It has raised doubts about the tribunal's legal authority for completing the exhumation of a mass grave of Croatian victims of suspected Serbian war crimes in Vukovar. Future investigations, and therefore prosecutions, are also likely to be undercut. To make things worse, the Venezuelan appointed to be chief prosecutor has now renounced the job to pursue apolitical career. This means further delay.

International leaders are engaged in a monumental whitewash of Serbian and Croatian leaders for reasons of political expediency, to keep them at the negotiating table.

Reluctant to use air strikes or other military intervention, Western politicians offer these leaders a new respectability and the promise of eventual financial support, grateful for any indication that they will stop the atrocious war.

Many of the international negotiators who initially went along with the idea of a war crimes tribunal probably never thought of it as a practical possibility, but as a convenient way to silence human rights activists and other supporters of the Bosnians. Perhaps they thought the tribunal could be used later as a bargaining chip to win Serbian and Croatian agreement to a peace settlement.

For cntics of the West's cowardly stance during this savage war, however, the tribunal mattered: It offered some prospect of accountability.

Although it was never likely that the paper trail would exist to implicate top officials, the successful prosecution of field commanders and local extremists who encouraged mass rape and murder might have begun a healing process after the war.

Now, though, the neutering of the international tribunai is under way. Only a facade will remain, it seems - one that can be counted on not to produce embarrassing prosecutions. A neat Machiavellian bargain.

Consider the separate agreement signed last year by the Bosnian Muslim leader Fikret Abdic with Serbia. It is an indication of what an eventual peace treaty between the warring parties could encompass. The agreement states that each side will prosecute its own. and that each regards the conflict as an internal matter.

The implications for potential war crimes trials are significant. Under international law, only international wars can produce suchFortunately, the tribunal also has jurisdiction over two other categories of crimes - genocide and crimes against humanity, the latter covering crimes such as mass rape.

For these categories, international prosecution overrides national law. Yet even here jurisdiction without political will is ineffectual.

The goal of prosecuting and punishing offenders must not be abandoned. It is not only a question of punishing barbaric crimes. It is just as important that we have a complete historical record of the war. We owe it to the victims, we owe it to ourselves and we owe it to history.

Above all. by insisting on such a record, we reassert our own humanity and decency and declare solidarity with those who have suffered.

We also send a strong message to other potential violators. There must be a clear threat that even if these criminals remain protected at home, they will be pariahs abroad.

The latest outrage in Sarajevo requires an immediate response by the United Nations and NATO. But it requires more than that. An attack of that scale on civilians is a war crime. It urgently reminds us of the need for a strengthened international tribunal that can pursue a full investigation and bring those responsible to justice. - Sadruddin Aga Khan -

(The writer was the United Nations high commissioner for refugees from 1965 to 1977. He contributed this comment to The New York Times)