The past -- or a frightening shadow of it -- has come back to life.

Long-standing legal protections that shielded former military personnel from prosecution were removed last year, allowing a series of trials related to the "dirty war" to go forward. The first to face prosecution, an officer with the Buenos Aires provincial police, was recently convicted, and many more people are awaiting their days in court.

A witness in the officer's trial, a 77-year-old bricklayer who testified to being tortured by the military, has been missing for a month and is feared dead. In recent weeks, judges and prosecutors have received threatening letters demanding a halt to the trials.

At the same time, backers of the former military government complain that their opponents, who now control the government and its courts, are persecuting them in the name of vengeance. History hasn't been sympathetic to them, and many say that the trials represent their last chance to voice their argument: that they were the victims of the conflict, attacked by dissident terrorists bent on destroying the country they were trying to protect.

A look at people representing those conflicting points of view -- one a judge leading the trials, the other a retired military officer opposing them -- illustrates how a violent conflict that officially ended more than 20 years ago continues to evolve, anger and terrorize those who were caught up in it.

The Judge

Shortly after Judge Carlos Rozanski walked into his chambers one morning last week, his telephone rang. Considering the angry and ominous calls he has been getting lately, simply answering could have been an invitation to trouble.

But this caller wasn't threatening.

"He's scared," Rozanski said.

It was one of Rozanski's witnesses, a man who had agreed to testify about the human rights abuses he had suffered as a dissident in this riverside city south of Buenos Aires. The disappearance of the bricklayer, also one of Rozanski's witnesses, had led many others to think twice about talking to the judge.

"He's worried about his family," Rozanski said shortly after the call. "This is the effect of terror."

Rozanski, 55, has been learning more than he'd like about those effects, he said, since he delivered the second guilty verdict against a former officer charged with systematic human rights abuses. He had recently received a letter that left him worrying about his own family:

"This farce will end soon," the letter read, "and those who have not honored their posts will be accountable to a particularly impartial court."

Rozanski admitted that the letter -- combined with the unexplained disappearance of the bricklayer, Jorge Julio López -- surprised him. When he began working on the trial, he said, he expected some minor resistance, but nothing serious.

"In one sense, maybe we were all wrong to underestimate the power of the reaction among some groups who oppose these trials, even though a majority of the country supports them," he said. "Maybe the reason that we overestimated ourselves and underestimated the reactions of others is that 30 years went by without justice. That does some very complex and powerful things to people. A trial like this isn't just a legal matter -- it is a lot deeper."

Now a security guard is stationed outside Rozanski's house, the personal price he's paying for reopening wounds that are two decades old. But he said he believes his ambition is worth it. Revisiting the wounds is the only way to get them to heal, he said, even though it might be painful for some -- and tragic for others -- in the short term.

"It's difficult, because we're telling the witnesses, 'Come and testify, it will be good for you to get everything off of your chest,' and at the same time there are all of these threats," Rozanski said. "It disorients the witnesses. I think some of them probably are going to desert the process, but the majority will remain."

Some of those witnesses are also accepting personal security guards, but just as many are refusing them. It's not because they aren't scared. It's because, they say, history has taught them to fear security guards -- a group often associated with the military in the past -- more than anything that might threaten them.

"You can't forget that in Argentina, we're talking about a history of state-run terror," Rozanski said. "It makes things a lot more complicated."

The Critic

Emilio Guillermo Nani is one of those working in the security industry who probably wouldn't be trusted by some of the witnesses. But then, he wouldn't trust some of them.

He is a security consultant now, but he used to be a lieutenant colonel in the Argentine army. The experience fundamentally shaped the way he views the past, just as it shaped the way he sees the present -- he wears a black patch over what used to be his right eye, which he lost in action when he was sprayed with shotgun pellets.

"In the 1970s, I was a captain and I lived it all -- the attacks, the bombs going off at government buildings, the assassination of my boss in Mar del Plata," said Nani, 60. "He died in my arms."

Since then, officially sanctioned reports, backed by mountains of evidence collected from thousands of witnesses, have detailed brutal abuses of power by the military during the dirty war. Between 9,000 and 30,000 people are believed to have been "disappeared" by the military, depending on the source.

Nani says he believes such accounts have become widely accepted as facts not because they are true, but because history is always written by those in power. He acknowledges that there might have been some excesses on the military's part -- unfortunate events happen in every war, he said -- but he insists there were just as many abuses by leftist groups that he considered the enemies of a sovereign government. Many of those listed as disappeared, he said, were terrorists who simply moved to other countries and changed their names.

"They weren't housewives and students -- they were military organizations," Nani said of the dissidents. "They wore uniforms, had hierarchies, flags, emblems and doctrines."

To begin rewriting that history, Nani helped organize a rally last week in Buenos Aires's Plaza San Martin, where several thousand supporters of the military honored the soldiers and police officers who died during the dirty war. They were heroes, Nani said, who died fighting a war on terror.

Now, he said, the terror is back. He said he believes that the threats Rozanski and other court officials received were probably penned by their friends in power, not anyone associated with the military. And the disappearance of the witness López, he said, might have been arranged with the elderly man's consent.

"It's a smokescreen," he said. "The government is the only one that would benefit from López's disappearance."

But the fear that the witness's disappearance has generated indirectly aids an argument that Nani has long made and that the courts are now working to counter: that refocusing attention on the dirty war only fans the embers of a conflict that has been cooling for two decades.

If the trials continue -- Rozanski and others vow they will -- Nani will continue to demonstrate peacefully against them, he said. Before it's too late, he added, he will try to do what he can to establish that it was the members of the military, not the dissidents, who were the victims.

"People are getting to the point where they are fed up," Nani said. "You can't pull on a rope eternally without the fear of it breaking loose."