The resignation of Richard May, the chief judge in Slobodan Milosevic's trial, has added a serious complication to proceedings that, after two years and 300 witnesses, are a long way from finished. One of three judges at the special tribunal for the former Yugoslavia, Judge May, of Britain, retired for health reasons just as the prosecution rested its case a full year later than expected. The delay was caused by the volume of the accusations, and Mr. Milosevic's defiant tactics and repeated illnesses. Even if the judge had not stepped down, Mr. Milosevic was expected to use his defense for maximum theatrics and propaganda. Now Mr. Milosevic, the former Yugoslav president, has grounds to demand an entirely new trial, or even a mistrial.

How this plays out is critical, not only in the interest of bringing him to justice, but also for any future prosecution of dictators - like Saddam Hussein - by international courts. One function of the tribunal is to serve notice on all mass murderers that they will not escape justice, even if their own people are unable or unwilling to serve it.

That is why it is imperative to examine why this trial has run into such problems, and why international justice has proved so elusive. The courts for the former Yugoslavia and Rwanda have been ad hoc affairs, set up to judge specific atrocities. Stalin, Idi Amin and Pol Pot died without answering for their crimes. Mr. Milosevic has played heavily on such moral ambiguity, denouncing the Hague proceedings as a victor's trial.

The problem is compounded by the hostility of the Bush administration to the new International Criminal Court, set up to step in as a last resort if a country fails to try its own major miscreants.

Another problem revealed by the Milosevic trial is the discrepancy between the horror of mass murder and the dispassionate proceedings of a courtroom. When there are thousands upon thousands of tortured corpses, it seems almost obscene for a dictator to be in the dock in a business suit, wrangling over technicalities. To be sure, there is merit in setting the calm majesty of the law against the violent tawdriness of evil. But when mocked or exploited, as it has been by Mr. Milosevic, the law can seem helpless and inadequate.

Serious as they are, these problems must not become an argument against international justice. With Mr. Hussein awaiting trial, and Osama bin Laden, Kim Jong Il and Charles Taylor of Liberia still out there, the world must believe that global justice is at least possible, if not likely.