The Act of Killing, Joshua Oppenheimer’s documentary on the 1965-66 mass killings in Indonesia, took the film festival circuit by storm after its release in 2013. Screened at more than 100 film festivals, picking up a BAFTA and an Oscar-nod for Best Documentary, the non-fiction film has stunned audiences and disturbed the Indonesian government. In what is touted as a radical approach to documentary-making, the film traces the story of the Indonesian genocide through the eyes of Anwar Congo, a perpetrator who has killed hundreds of ‘communists’ wanted by the then government. What follows in the nearly three-hour film is a horrifying surreal re-enactment of the killings that left more than a million people dead; an episode of history suppressed systematically by the Indonesian government. In a phone interview, American filmmaker Joshua Oppenheimer speaks on the film’s impact, the nature of impunity and why “we are much closer to the perpetrators than we would like to think”. Excerpts from the interview:

Tell us about the film’s reception. Many countries, for instance Germany and the US, have suppressed parts of their own history. Did you sense that in the way audiences reacted?

It’s very specific. You can’t see broad differences between Europe and Asia. The reaction in Indonesia has been the single most powerful and important reaction in the world. The film has utterly changed the way the country is talking about its past. The key variable is to know to what extent audiences are invested…in official histories that deny their country’s role in perpetrating atrocities. So, some countries that have been involved with genocide and absolutely deny it… the public knows that the official history is a lie. In other countries, ordinary people are invested in telling stories denying their involvement with atrocities and for those countries, the film has been challenging.

It all boils down to people, for audiences to approach Anwar Congo through my intimacy with him and to empathise with him, to think that we are all much closer to the perpetrators than we’d like to think. The perpetrators are human, including their morality.

Even nationality plays a part in the practice of evil. These are some of the painful truths that the film uncovers. For example, in Germany, real work has been done in the last 50 years to reconcile with what they did as a nation. Overall, I’ve been impressed with audiences who are allowing themselves to identify with a man like Anwar.

After the film, the Indonesian media sent its reporters to collect and document stories of these atrocities, strong editorials have been written… how has the government taken all this?

In a way, the government in Indonesia has been disappointing. On one hand, the government hasn’t banned the film, because of the cultural, political and media support for the movie, I think. They have also not brought in the army generals who would have threatened to kill people.

But, there’s been no movement against Pancasila Youth (one of the main organisations involved in the killings), no movement against the corruption, nothing against gangsters… the leading candidate for the presidential elections this year is accused of the mass murder of students in 1998.

You lived in Indonesia for nearly a decade, and filmed The Act of Killing over five years. How is it possible for a people, a country to forget genocide?

One of the chilling findings of the film is the consequences of denial. Anwar Congo and his friends, the perpetrators of the 1965 genocide, in general, have written a victor’s history to justify what they’ve done. And it’s done so, in part, because they are human beings and being human they know what’s right and what’s wrong. To avoid living most of their lives in anguish, like Adi Zulkadry (Anwar Congo’s friend) who says in the film that killing is the worst thing you can do, but if you are paid enough it becomes an excuse and you can lie to yourself. In keeping that lie, it only leads to a downward spiral of corruption and moral vacuum. After you’ve justified the killing, you now have to blame the victim to say it’s their fault and the worst part, you’ve to kill again, because if you don’t, it’s an admission that it was wrong the first time. The horrible thing here is the continuation of evil. Ordinary people know better than to remember events that are dangerous to talk about. The conditions in which forgetting a genocide become possible is a condition of moral and cultural vacuum, which you can see in the film. But the world in which we forget any genocide is an apocalyptic one.

You interviewed many perpetrators, Anwar was the 41st. How did he become your central character?

In my investigations, I tried to go deeper and it wasn’t that I was looking for the right character… but I lingered on Anwar because I felt that his pain was close to the surface. By this time I recognised that the boasting (by perpetrators) was not a sign of pride but a desperate need for them to feel that what they did was right, and that opened up a whole new understanding. I sensed that in Anwar, because the first day I met him he danced on the roof (after he showed how he killed his victim using wires), it was an extraordinary example of impunity, exactly what the survivors had told me earlier. In this boasting, you find a metaphor for a regime of impunity. So, instead of moving on to another perpetrator, I did something unique… I showed him the footage of himself on the roof which I had not done with any of the others. And that sent us down a rabbit hole for five years of my life and his life and led to 1,200 hours of footage.

I showed him the footage hoping he would recognise himself, recognise the meaning of what he’s done. He was very disturbed but he dares not say it is awful. So he proposed changes to his clothes, he talked about improving his acting. He made the scene better, more cinematic, more fun. He kept proposing embellishments in which I saw an even more powerful metaphor for impunity… all the way to the final scene.

If this film hadn’t happened for Anwar, how would he have dealt with his guilt? As you say, his conscience is rattled, he is disturbed…

Anwar would’ve still been tormented by nightmares. It’s very frightening for Anwar… but above all, it doesn’t matter if it’s good for Anwar or not. The film is not a therapy for Anwar or other perpetrators. In this year’s presidential election, I think Anwar will be campaigning for some of the worst candidates and is already offering his celebrity support to them.