A quarter of a century ago, the Bosnian Serb army seized the UN-designated safe area of Srebrenica. In the days that followed, some 8,000 Bosnian Muslims, mostly men and boys, met their death in a massacre that is regarded as the most severe war crime in Europe after World War II. The International Criminal Tribunal for the former Yugoslavia (ICTY) tried to bring politicians, generals and members of militias to justice for the crimes committed in the wars during and after the breakup of Yugoslavia in the 1990s. At the forefront was Serge Brammertz, who served for ten years as the Chief Prosecutor at the ICTY.

Deutsche Welle: Mr. Brammertz, a quarter of a century has passed since the Bosnian Serb army abducted and killed thousands of people, mostly men, in the UN-created "safe area" of Srebrenica. After all these years: Do you see any signs of reconciliation?

Brammertz: Well, the reconciliation is a very complex and tricky issue; it's an aspect you need to look at over time. The unfortunate reality is that I think today we are further away from reconciliation in the traditional sense than 10 years ago, especially because we see today glorification of war criminals and denial of the existence of crime, which is much more prominent and much more tolerated today, much more than five years ago.

Read more: Bosnian Serb leader Dodik disputes Srebrenica genocide 

The ICTY had 5,000 witnesses, over 10,000 trial days. It was the biggest trial since the Nuremberg trials. Why doesn't it convince people in the Balkans that there have been atrocities and that the people they are glorifying as heroes are war criminals?

No, it is really a very unfortunate situation. We have seen it in the courtroom with people like (former leader of Bosnian Serbs) Radovan Karadzic and others who, when they take the floor, saying we are not here to represent ourselves, we are representing our people — the Serbian cause or the Croatian cause of the Bosnian one. We as the tribunal have always made sure that we explain that we prosecute individuals for their individual criminal responsibility, for their own crimes.

We see, like in many places of the world, nationalism being a major factor. As long as we see that history books in the different countries of the former Yugoslavia, even history books within Bosnia-Herzegovina, have different histories about the conflict .... Well, how can you hope or imagine that there is a reconciliation? Because to start reconciliation, you need the same understanding about the past and the same understanding about responsibilities.

Sometimes I am getting this critical question saying: Not only has the tribunal with the 161 indictments and more than 90 convictions, not only have you not contributed to reconciliation, but you almost prevented reconciliation. Because every time a judgment is coming out in The Hague, one group is satisfied, the other not satisfied. My answer to this is always: Justice alone can never, ever lead to reconciliation. Reconciliation needs to come from within society, from the different groups — the victims' groups, the perpetrators' groups. And you need responsible politicians to make this possible. The prosecutions and justice and accountability are really a starting point. It's a condition sine qua non, without which reconciliation has no chance.

I think that what we have done is extremely important, because [there are] those who are now denying even the genocide. The ICTY and the International Court of Justice both have, in the highest instances, decided that what happened in Srebrenica is genocide. I think it is a precondition that there is accountability, that there is a clear understanding about responsibility for the conflict.

Read more: Srebrenica 'a terrible crime' but not genocide, Serbian PM tells DW

But still, the sad reality is that the majority of convicted war criminals are seen as heroes by their own communities. There is nothing heroic about those people who have been prosecuted in The Hague. They are prosecuted because they violated the Geneva Convention, which means that they executed prisoners, destroyed private homes, tolerated or even encouraged massive sexual violence. Everyone who has been convicted in The Hague is the exact opposite of what one would conside, as being a hero.

You mentioned the criticism of the tribunal. It has been accused of being biased sometimes in that it mainly went after the Serb perpetrators.

The tribunal, like all the international tribunals, is not perfect ... The reality is that the majority of persons prosecuted and convicted are from the Serbian group, mainly Serbs from Bosnia-Herzegovina. But there have been individuals — considerably fewer, of course — convicted also from Croatia and also from Bosnia. We really make it very, very clear that crimes have been committed by all sides at different moments of the conflict.

Since reconciliation is not among the accomplishments of the ICTY, after those nearly 25 years of the international tribunal, what do you see as its biggest accomplishment?

From my time in office since 2008, the biggest accomplishment is definitely the arrest and subsequent prosecutions and convictions of Karadzic and Ratko Mladic. I understood during my many meetings with the survivors and mothers of Srebrenica that no one could bring back their loved ones, but that the prosecution and before that, the arrest of Karadzic and Mladic was really their main demand.

A second achievement comes through all those thousands of witness statements, the expert reports, ballistic reports, forensic reports. We have very clear historical documentation and factual and legal documentation about what really happened in the former Yugoslavia. If we would not have this overwhelming information, there would be very little to confront today the denial and glorification of war criminals.

The Tribunal was set up in 1993, two years before the atrocities in Srebrenica. This apparently had no deterrent effect on the perpetrators.

When the genocide in Srebrenica in July 1995 happened, the tribunal had indeed started working. But for security reasons, it was almost impossible to conduct investigations on the ground. Which means that the first investigator of the tribunal was only at the Srebrenica mass graves one year later. But at the time US Secretary of State Madeleine Albright was showing satellite imagery in the [UN] Security Council about places where we thought mass graves would be.

The information which was available to my colleagues was that almost 8,000 men and boys had disappeared and no one knew where they were. Then there were eight witnesses which survived those massive shootings, who had been shot and who had spent all day in a mass grave covered by many other bodies and who at night could escape and survive. So those are the few, the handful of survivors from Srebrenica, who have testified in those different cases.

When the first investigation started one year later, thanks to those testimonies and thanks to satellite imagery, there were only a few hundred bodies found in those mass graves. During that one year, where no investigator could go on the ground, those thousands of bodies had been moved from a handful big mass graves to dozens of secondary and tertiary graves in order to conceal the crime and to try to show that it was not as massive as people were thinking. One of the challenges of the investigation was to link those secondary graves to the primary graves, to really establish that more than 1,000 or 2,000 people were killed at one place.

As a result, we had soil sample analysis and cartridge bullet analysis, to determine that the ones in the main grave were shot by the same weapon as the one in the secondary graves. This is really the macabre part: We have more than 1,000 DNA analyses where body parts that we found in the secondary graves could be linked to body parts in the primary graves. So one of these tragedies is that many bodies were torn apart and that different body parts of the same individual have been found at different places.

You can't imagine the tragedy, what it means for family if you receive not just one call that your son or your husband has been found, but several times — and then we only speak about body parts. It's unimaginable; it's difficult to imagine the suffering that this inflicted on the survivors.

Read more: Hague tribunal ends prosecution of Yugoslav war crimes but legacy lingers

Obviously, you must have gone through many emotional moments during your time as chief prosecutor. It's obvious listening to your descriptions.

My most emotional moment was definitely my first visit to Srebrenica in 2010. I had already met a few times with the mothers of Srebrenica. But I spent one day there, walking with the survivors through the gravesite. I visited some of the places where the mass executions took place. I spent hours and hours with survivors individually; they were showing me the last pictures of their loved ones, telling me their stories and seeing the pain still so many years later in the eyes of everyone.

This happened 25 years ago. But for the victims and survivors, their lives somehow stopped with the genocide. And it's in the center of their life since then, every single day.