THE HAGUE, Netherlands -- Three years and eight months into the war crimes trial of former Yugoslav President Slobodan Milosevic, the courtroom still crackles with explosive outbursts.

"You know perfectly well those people were butchered!" prosecutor Geoffrey Nice shouted at a former Serbian police chief this month while questioning him about the deaths of more than 40 ethnic Albanians in the Kosovo village of Racak during the winter of 1999.

"This is preposterous!" shot back the witness, Bogoljub Janicevic, his wire-rimmed glasses sliding down his nose.

On the opposite side of the courtroom, on the fifth anniversary of his fall from power in Belgrade, the white-haired Mr. Milosevic sat impassively. But his face darkened several shades of red, as often happens when testimony heats up.

As Iraqi prosecutors prepare for the trial of former President Saddam Hussein, scheduled to begin in Baghdad today, Mr. Milosevic's slow-moving case at the U.N. Balkans war crimes tribunal demonstrates the many pitfalls entailed in trying deposed leaders in a court of law: The defendants drag out their cases, they can intimidate witnesses, and any links to atrocities are usually concealed by layers of subordinates.

For the International Criminal Tribunal for the former Yugoslavia -- the first international war crimes court established since the Nuremberg and Tokyo trials after World War II -- the long-running Milosevic courtroom drama is both a cause of the toughest criticism the tribunal has received and a symbol of its greatest success.

"The slowness sometimes doesn't give us the best image," Theodor Meron, president of the 25-judge tribunal, said in an interview. "But this is truly an historic case."

Speaking of the Iraqi court, Judge Meron said it would have to guarantee the rights of its famous defendant to be credible: "Any court dealing with atrocities has to pay particular respect to due process. There can be no cutting corners."

Judge Meron, who was born in Poland, spent four years in a Nazi prison camp as a youth.

The prosecution of Mr. Milosevic and 125 other people by the 12-year-old tribunal is creating a body of law that many legal experts say will serve as a guide for future war crimes tribunals worldwide. Iraqi judges and officials from war crimes tribunals newly established in Africa and the Balkans have consulted court officials recently.

The length and complexity of the Milosevic trial helped convince Iraqi prosecutors that they needed to concentrate on a few key events rather than attempt to cover the full range of alleged atrocities during Saddam's 24-year rule, legal experts and observers said.

Mr. Milosevic, 64, is charged with 66 counts of genocide, war crimes and crimes against humanity spanning the 1991-95 war in Croatia, the 1992-95 war in Bosnia and the 1998-99 Serb crackdown in Kosovo. He could face life in prison; the court does not impose the death sentence. He denies the charges.

The volume and complexity of the hundreds of thousands of documents and exhibits in his case and others at The Hague have brought about some of the most high-tech courtrooms in the world. Transcripts appear on judges' computer screens minutes after words are uttered.

But one of the greatest obstacles for prosecutors is the sheer force of the personality on trial, said Florence Hartmann, spokeswoman for the Yugoslavia tribunal's prosecutors and a former French newspaper reporter who wrote a book about Mr. Milosevic. Many witnesses at The Hague, like the onetime police chief, are Mr. Milosevic's former subordinates.

"Witnesses address him as Mr. President," Ms. Hartmann said. "Milosevic plays to the court, and Saddam Hussein will play to the court. They don't forget they were president. They don't feel what they did was a crime."

In the cases involving former heads of state, prosecutors often have no direct evidence tying the defendant to specific acts. "You have to find the invisible ropes they're pulling," Ms. Hartmann said. "It's their orders that lead to the crimes. You have to find the insiders, and that's the most difficult."

The judges, frustrated with the pace, have urged prosecutors to trim indictments to a manageable number of strong claims, but they refused. "To shorten the indictments doesn't respect the victims or the reality of what that guy did," she said.

Prosecutors have called on 295 witnesses, including sobbing victims of atrocities; Gen. Wesley K. Clark, the former NATO commander; and Milosevic insiders, who testified in closed sessions under protective custody.

The prosecution's exhibits have created an archive of eyewitness accounts and often-gruesome photographs and videos of some of the worst atrocities in Europe since the end of World War II: the slaughter of an estimated 8,000 Muslim men and boys in July 1995 in the Bosnian town of Srebrenica and the relentless shelling of Sarajevo.

The former Yugoslav president has used the trial to condemn NATO, the United States and the European Union for supporting the Kosovo Liberation Army, which he and his witnesses refer to as terrorists.

Denying culpability in any of the wars, he has used defense witnesses and documents to try to demonstrate that he had no control over local police or army officials who might have committed crimes.