Recently declassified official British documents revealed the United Kingdom's 1965 intelligence operation to spread disinformation about a coup plan by a council of generals against president Sukarno. The campaign prompted some junior officers to pre-emptively kidnap and kill six generals.

The Army quickly retaliated, blamed the move on the Indonesian Communist Party (PKI) and led the carnage that ensued, killing more than 500,000 PKI members and supporters. Sukarno was toppled nevertheless when general Soeharto grabbed power the next year. The British campaign continued with operatives putting out newsletters, purported to be written by Indonesian patriots, urging the elimination of the PKI, according to the documents.

In 2017, declassified United States government documents from the same period showed its embassy in Jakarta giving money, equipment and a list of communists to the Army. The embassy also had full knowledge of the mass killings, but did not try to stop them.

Although these documents must still be verified by historians, the Cold War psyche makes these reports plausible. Britain was at war with Indonesia over the “confrontation” that Sukarno had waged against the creation of Malaysia. Worried about Indonesia falling into the communist bloc, the US had been trying to depose left-leaning Sukarno.

The extent of their involvement is not clear, and what Britain and the US decide to do with these revelations is for them to decide. But this should be a guilt trip for Indonesia too.

The government has consistently quashed all attempts to bring out the truth about this national tragedy.

In 1999, then-president Abdurrahman “Gus Dur” Wahid issued a public apology for the role that Ansor, the youth wing of Nahdlatul Ulama (NU), played in the massacre. Gus Dur was NU chair before becoming president. After his death in 2009, NU, Indonesia’s largest Islamic mass organization, retracted his apology.

In 2004, the House of Representatives enacted a bill on the formation of a truth and reconciliation commission to look into the 1960s killings, only for it to be annulled by the Constitutional Court in 2006.

In 2012, an investigation by the National Commission on Human Rights (Komnas HAM) ruled that the killings were a gross violation of human rights and a crime against humanity. The government never followed up its recommendations, which include an apology to the victims of the massacres.

In 2015, human rights activists formed a people’s tribunal in The Hague to bring out the truth, 50 years after the tragedy, and came up with a number of recommendations. The government of President Joko “Jokowi” Widodo ignored the tribunal, which blamed the killings on the state and the military.

Although news stories of the declassified British documents made the rounds on social media, they did not cause a ripple. Either we Indonesians have become too numb to see the horror of the killings, or we simply cannot handle the truth.

The ghosts of those slain, meanwhile, will continue to haunt us until we admit our collective guilt.