His name might not be as infamous as “Milosevic” or “Saddam,” but the fight against impunity claimed another “first” earlier this month. Efraín Ríos Montt, a former Guatemalan general, became the first former Latin American president convicted of genocide and war crimes, extending the long arm of justice to another corner of the world, for at least a moment in time.

It was only a moment, because about a week after Ríos Montt was sentenced to 80 years for the slaughter of nearly 2,000 Ixil people (an indigenous Mayan ethnic group), Guatemala’s constitutional court overturned the conviction due to technical issues, in effect, calling for a retrial. This was despite the fact that the earlier ruling found that during his time in power, “Ríos Montt had full knowledge of everything that was happening,” including the torture and killing of the Ixil, “and did not stop it.”

The former dictator had enjoyed immunity from investigation for nearly 15 years, while he served as a Guatemalan congressman, even though a number of inquiries conducted had found him responsible for atrocities. In 2001, international human-rights organizations filed an application with the Guatemalan Public Ministry to spur an investigation into past crimes. When Ríos Montt lost power — and his immunity — in 2012, the Guatemalan government moved quickly to haul him into court.

In many ways, Ríos Montt’s initial conviction was the first step in delivering some sense of justice to the victims of a bloody civil war, where impunity has long-shielded human rights violators from the long arm of the law. And despite this week’s setback, it constitutes not only a win for the human-rights advocates in Guatemala, but also for those internationally.

Referring to the initial judgment, David Tolbert, president of the International Center for Transitional Justice, stated, “This was the first time that a former head of state has been tried for genocide in clearly genuine national proceedings . . . [It] . . . shows the importance of justice being done nationally, even when the odds are long. It is a great leap forward in the struggle for justice in Guatemala and globally.”

Tolbert speaks from experience. A former deputy prosecutor at the U.N. war crimes tribunal in The Hague, he is part of an ever-growing “Hague alumni” community that began with the Slobodan Milosevic prosecution, who are both well informed of the challenges of heads-of-state prosecutions, and aware of their unique role in fighting the impunity that, for most of human history, has been the norm.

Thus, whatever the final result of the Ríos Montt case, the fact that he faced a courtroom trial, at all, is historic, as he is part of a critical international trend that is targeting those heads-of-state who, traditionally, were those most likely to escape justice. Because today, the question is not if another former leader will ever be charged, but rather when, and who is next?

This is a fundamental change in the presumption. For centuries, dictators acted with impunity, perpetrating atrocities without fear of prosecution. But unlike those of us who studied in the 20th century — the next generation will only know a world where such terrible dictators actually do stand trial. Such a presumption will embolden the next generation of leaders to act — and perhaps with time — bring a true end to impunity.

Such an end does not depend on any one trial. When Milosevic died, just months before his trial was to conclude, I was disappointed. But then it occurred to me, the “Butcher of the Balkans,” the most powerful man in Yugoslavia, in the end, died in a prison cell, yearning to be free — and arguably changed the arc of history. That is because today, we are not surprised by a trial in Guatemala, nor would a trial in Syria cause shockwaves. And that we are starting to expect justice might be the biggest change of all.

Mark V. Vlasic, an adjunct professor of law and senior fellow at Georgetown University, served on the Slobodan Milosevic prosecution trial team at the U.N. war crimes tribunal. A former White House Fellow to Secretary of Defense Robert Gates and adviser to the President’s Special Envoy to Sudan, he leads the international practice at Madison Law & Strategy Group.