The president of Croatia, Stipe Mesic, testified Tuesday against his old rival, Slobodan Milosevic, at the former Yugoslav leader's war crimes trial in The Hague. President Mesic blamed Mr. Milsoevic for the violent break-up of Yugoslavia in the early 1990s.

The dramatic scene was set even before Stipe Mesic entered the courtroom. Slobodan Milosevic verbally bashed his long-time adversary by calling him a problematic witness because of what Mr. Milosevic characterized as his personal and criminal role in the break-up of Yugoslavia. But President Mesic has long said he'd relish the opportunity to testify against Mr. Milosevic, and he finally got his chance.

Stipe Mesic was the last president of Yugoslavia before it broke apart in 1991, violent events that prosecutors, and President Mesic, attribute to Slobodan Milsoevic.

In court Tuesday, a composed Mr. Mesic portrayed the former Yugoslav leader as a cold, unfeeling man who was only interested in attaining his goals. "Well, I am quite certain Milosevic didn't favor any kind of Yugoslavia that would be federal or confederal," he said. "That was not what he wanted."

Stipe Mesic was the president without any power. He testified that as the legal head of Yugoslavia, he struggled to keep his country together. But in the end, he was no match for Mr. Milosevic, whose army, said Stipe Mesic, even prevented him from traveling to state meetings.

Mr. Mesic said in the years leading up to war, Slobodan Milosevic staged one coup after the next to break the country apart. He said that Mr. Milosevic was the first to declare Yugoslavia dead and to hint at the coming use of force.

He also said that Mr. Milosevic ignored the federal constitution and set up his own rump presidency with his own hand-chosen politicians. In addition, the Croatian leader added, Mr. Milosevic turned the Yugoslav army into his own Serbian fighting machine.

In the end, said President Mesic, Mr. Milosevic managed to incite the Croatian Serbs in the Krajina and other areas to violence, using them as a fuse to ignite war in neighboring Bosnia. He promised them their own Serb state, said Mr. Mesic, but they were in fact just pawns in his plans with former Croatian President Franjo Tudjman to carve up Bosnia.

Prosecutors presented many documents they say back up their claims. Richard Dicker of Human Rights Watch points out the documents alone aren't enough to convict Mr. Milosevic, but he wouldn't expect them to be.

"The only documents by [themselves] that would do the job would be the ones that said kill all damn Croats in Krajina, [Signed] Slobo," he said. "And there [aren't any such documents]. Documents are important and will loom large in the prosecution's case. Did they nail Slobodan Milosevic's guilt? No, I don't think so. Prosecutors will have to fill in holes, make some connections, but that's what prosecutors get paid to do."

Slobodan Milosevic will get his chance to question President Mesic on Wednesday. Sparks are expected to fly as the two politicians, and their diametrically opposed versions of recent Balkan history, clash in the courtroom.