LA PLATA, Argentina -- Argentina is putting its past on trial this year, probing the memories and consciences of those who lived through its bloody "dirty war," which pitted a military government against thousands of dissidents in the 1970s and '80s.

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.