Of the 78 people on all sides publicly indicted for war crimes in the former Yugoslavia, 66 remain at large. They include General Ratko Mladic, who personally presided over the slaughter in Srebrenica, and Radovan Karadzic, the political mastermind of the Bosnian genocide. NATO knows where to find these and other accused killers and has the legal duty and the means to capture them.

Of the 78 people on all sides publicly indicted for war crimes in the former Yugoslavia, 66 remain at large. They include General Ratko Mladic, who personally presided over the slaughter in Srebrenica, and Radovan Karadzic, the political mastermind of the Bosnian genocide. NATO knows where to find these and other accused killers and has the legal duty and the means to capture them.

But with the exception of NATO's first arrests of suspected war criminals Thursday (one of whom was killed), Western political leaders have refused to order their arrest. If peace is to endure beyond the planned withdrawal of NATO troops in June 1998, the indicted war criminals must be apprehended.

Many suspects - including Mr. Karadzic and General Mladic - enjoy not only freedom but power: They obstruct the return of refugees, suppress dissent and use violence and intimidation to enforce their vision of ethnically ''pure'' states. As long as the suspected war criminals keep their influence, real peace is impossible and any NATO exit strategy is doomed to fail.

Many Western leaders, including NATO Secretary-General Javier Solana Madariaga, argue that arresting indicted war criminals is the responsibility of the region's governments, not international troops. However, all the unarrested defendants have taken refuge in areas controlled by forces of their own ethnicity, which, in turn, refuse to arrest them.

Despite considerable financial pressure, neither the Republika Srpska, where most of the suspects live, nor Serbia has handed over a single indictee, and Croatia has surrendered only two. While tough and sustained financial pressure on Zagreb may yield further cooperation, Pale and Belgrade have indicated that they will never cooperate regardless of the financial pressure imposed. To say that it is up to the local parties to make arrests is effectively to say that there will be no arrests.

In a similar buck-passing maneuver, some Western military commanders have asserted that arresting indicted war criminals is a ''police function'' that should be divorced from the military duties of NATO troops. This betrays a disappointing lack of vision and an inadequate understanding of the contemporary requirements for international security and world order. Since the end of the Cold War, the most common reason for deploying NATO troops has been not to counter classic international aggression but to mitigate humanitarian hardship caused by highly abusive forces.

A functioning international system of justice is an essential tool for deterring such atrocities in the future - before it becomes necessary to risk the lives of international troops. Officials who contemplate mass murder are likely to think twice if they believe they may be brought to justice for their crimes.

Despite NATO's legal obligation to help arrest war criminals, political leaders have so far given NATO troops instructions to arrest only suspects whom they ''encounter.'' But even this mandate has proven farcical, as NATO troops go out of their way to avoid any such encounters.

The ''War Criminal Watch'' Web site (http:www.wcw.org/wcw/news/html) regularly updates the whereabouts of most of the suspects, a number of whom are living openly in the same towns where they committed ethnically motivated murder, rape, mutilations and expulsions.

Perhaps the most significant factor weighing on the minds of Western military leaders, particularly in Washington, is the risk involved in making arrests, especially the risk from Bosnian Serb troops. Most agree that NATO's superior firepower would overwhelm what portion of the disoriented and disillusioned Bosnian Serb army might be guarding the indicted war criminals. Instead, they fear retaliation later: sniping or hostage-taking directed against NATO troops or the many international workers in Bosnia. But this risk is both containable and necessary to take in order to avoid greater risks to the peace process and the prospects for a system of international justice.

To overcome the ''Somalia syndrome'' that is paralyzing the Pentagon, lleadership is needed from Europe. Many European militaries taking part in the earlier UN peacekeeping force suffered casualties in Bosnia. Europeans have shown that they understand the need to take some risks in order to avoid far greater ones down the road. European leadership is thus needed to overcome American shortsightedness and to ensure that the indicted war criminals are arrested before it is too late.

July 11, 1997

The writer is executive director of Human Rights Watch. He contributed this comment to the Herald Tribune.