THE HAGUE -- For almost three years, Chief Prosecutor Louise Arbour of the U.N. International Criminal Tribunal faced one irritating question at every press conference and every interview: Why had she not indicted Yugoslav President Slobodan Milosevic, and when was she planning to do it?

After she announced on May 27 that Milosevic and four other high officials were indicted for crimes against humanity and violations of the laws and customs of war, one of the first questions journalists asked was: Why now?

Quite simply, Arbour said, because her office now holds sufficient evidence that will withstand examination before the Tribunal once the indicted are brought to The Hague. The timing of the indictment, she said, was dictated only by the quality of that evidence, not any political motives.

Arbour also admits that the evidence behind the indictment is far from complete. It does not necessarily represent the final word on the responsibility of the five indicted political and military leaders. This is because the indictment against "Milosevic and others" only covers alleged crimes committed this year.

But Arbour says some of the indicted leaders could eventually be held responsible for certain earlier events, not only in Kosovo but also in Croatia and Bosnia and Herzegovina. The investigation, therefore, continues -- as do the Kosovo crimes.

The indictment is therefore likely to be widened and deepened at a later stage, particularly if Arbour and her team are allowed access to the scenes of crimes in Kosovo. If the present readiness of the Western governments to open their intelligence archives to the Tribunal continues, the case could expand into the Balkan wars from the first half of the decade.

If this is the case, why did Arbour not wait until she completed her investigation of the political and military leadership of Serbia and Yugoslavia, rather than raise an "incomplete" indictment put together in haste?

Arbour does not hide the fact that the prosecutor's office tried to process the available information as quickly as possible. But this speed does not appear to be motivated by an interest to increase pressure on Milosevic, as Belgrade representatives have charged.

Arbour was in fact in a hurry to pre-empt any political deal over Kosovo in which the interests of justice would be sacrificed at the altar of Realpolitik. There was plenty of evidence that just such a sacrifice was forthcoming: U.S. envoy Richard Holbrooke offered just such diplomatic immunity in his agreement with Milosevic last October.

Announcing the indictment, Arbour admitted that she had been "very concerned that these accused -- alone or with the assistance of others -- might succeed factually in putting themselves outside of the reach of the law, go somewhere, disappear. It was a source of concern that I thought was serious enough, that required us to deploy a particular effort in the office to lead this investigation to completion as quickly as possible."

Arbour obviously took seriously rumors of recent weeks that Milosevic was seeking a guarantee of immunity from international criminal prosecution -- or even a "golden exile" in South Africa or some other country -- in exchange for his assent to a political solution for the current crisis.

This is why Arbour requested Judge David Hunt, who confirmed the indictment, to issue an international arrest warrant, as well as a court order requesting all states to search for and freeze any assets of the accused, to prevent them from being used to evade justice. Judge Hunt accepted Arbour's request, and the court order has already been circulated internationally.