The lights went off for the "The Act of Killing" when it lost the Oscar for Best Documentary Feature to a feel-good tribute to struggling backup singers.

It shouldn't come as a surprise that with the dimming of publicity surrounding the documentary feature on death-squad leaders re-enacting their crimes in Indonesia's anti-communist purge of 1965, the memory of victims and survivors would also fade. The murder of nearly a million people with the backing of the CIA had been ignored for 50 years until "The Act of Killing" shocked viewers with the open boastfulness of the killers. To its credit, Hollywood has boosted the profile of the film, and the bloodletting, in a way that no previous reports or studies on the massacre have achieved. But now that the curtains are drawn, will the film share the same fate as its disturbing subject matter?

The families of victims are still around and cry for justice. The Indonesian government justifies the massacre on national security grounds and has refused demands for a criminal inquiry. It sat on its hands last year when a group called Anti-Communist Forum of Indonesia attacked and threatened to kill survivors gathering for a discussion. And just last month its armed forces broke off a discussion on Tan Malaka, Indonesia's former communist leader.

Anwar Congo, the main character in "The Act of Killing," grew up selling black-market cinema tickets. Later, he acted out his deeds with the image of John Wayne in mind, playing the good guy fighting the communist villains. One reason that motivated Anwar was that the Indonesian communists hated American movies. By focusing on the killers who identify themselves with the cowboys of the West, Joshua Oppenheimer, the director of "The Act of Killing," held a mirror to Americans suggesting that they may have more in common with the perpetrators than most like to think. What the film viewers saw was ugly, but it also shows the different paths the killers took to live with their guilt. At the end of the film, we see no redemption for Anwar Congo. As he slowly comes to realize that he'd done something terrible, his retching body does not give him release.

Oppenheimer and his fearless Indonesian crew dream bigger than the Oscar: They aim to bring justice for the survivors. As retaliation for an alleged communist coup, the Indonesian army, operating with the help of civilian death-squads, extinguished nearly the entire Indonesian left in a period of six months. They slaughtered union members, teachers, journalists, leftist artists, ethnic Chinese, and nearly all members of the communist party. The speed and scale of the killings are comparable to the worst recorded cases in modern history — six million Jews killed in eight years in German-occupied Europe and two million Khmers in Cambodia in four. But while the Nazis and Khmer Rouge have been defeated, and their atrocities universally condemned, the perpetrators of the Indonesian massacre have won and the Western world cheered on the bloodshed.

In a number of public screenings I attended — whether at Harvard or Columbia, an independent cinema in Brooklyn or at the Library of Congress — there was a sense of confusion and helplessness among the audience. They would often ask the director "but what can we do?" Oppenheimer would say they needn't look as far as Indonesia for the answer but at their own neighborhood.

It's no longer a secret that the West encouraged and supported the actions of the Indonesian army. The United States — at war in nearby Vietnam at that time — provided a list of people to be targeted for the Indonesian army and also equipment for their operations. At the height of the Cold War, America openly celebrated the annihilation of Indonesia's Communist Party, the third-largest after the Soviet Union and China, over a mountain of corpses.

The word amok has passed into international vocabulary from the Indonesian amuk, describing a state of murderous frenzy. Perhaps Western intelligentsia could learn more about the real-life background behind the grammar. The lasting experience of amok is not over till we break the silence following the horror.

Joshua Oppenheimer has called for the United States to break the silence and admit the role it played in the massacre. At least one senator, Tom Udall of New Mexico, heard his call and raised the possibility of releasing a "Sense of the Senate" resolution on the issue. While this might be a glimmer of hope for survivors to get the recognition they deserve, American citizens could take advantage of this gesture and call on their senators to ensure the United States discloses its involvement and finally comes clean.

"The Act of Killing" is a re-enactment of a nation's collective memory, a killer slowly comes to grip with the moral wrong of torturing and murdering hundreds of people. Neither Indonesia nor the United States has faced the truth so far. How long can we ignore what we know in our deepest hearts until we damage ourselves to a point of no redemption?

Prodita Sabarini, an Indonesian journalist, is the 2013-14 IWMF/Elizabeth Neuffer fellow.