IN A TRIAL that was a great triumph for human rights, a democratic Argentina brought to justice the military men who had brutally misruled the country in the previous juntas. That was five years ago. Now President Carlos Menem has carried out his unwise promise of last April to pardon and release even the most culpable of them.

Jorge Rafael Videla, president of the country during military rule, and former admiral Emilio Massera had been sentenced to life imprisonment. Roberto Viola, another former president, had been sentenced to 17 years in prison. Others were pardoned as well, but these names lead the list -- men who were directly and personally responsible for the atrocities that the armed forces and police committed, in the years of the juntas from 1976 to 1983, in the name of a war against leftist subversion.

These men were convicted, after a long and careful trial, of many counts of murder, torture and kidnapping. More than 9,000 people died in the hands of their forces -- some of them people who sympathized with the left, some of them only suspected of sympathizing, some of them people of no political interests whatever who were picked up in personal vendettas or sometimes by sheer error. It was an organized campaign of official hysteria and terror.

In a misguided attempt to show balance, President Menem has also released a genuine terrorist, the leader of the Montonero guerrillas, Mario Firmenich. That gesture offers nothing to the forces of democracy in Argentina and will serve only to reinforce the paranoia on the right.

The purpose of these pardons, according to Mr. Menem, is to promote the "reconciliation" of Argentina's people -- in other words, to assuage the grievances of the military extremists and fascists. In the seven years since the last junta fell there have been four attempted coups, the most recent in early December.

The greatest national threat to Argentina is this strange military establishment, operating as a state within the state with contempt for the civilian population that it putatively serves. It is difficult to think of any country on Earth with less need for large and aggressive armed forces. Its only combat against a foreign enemy in recent years was the fiasco in the Falkland Islands, which, incidentally, led to the collapse of military rule and the revival of democratic government.

That elected government, in the 1985 trial, reestablished the rule of law in Argentina. In contrast Mr. Menem's pardons deliver an ambiguous and more troubling message.