Who bears responsibility for the 1965-66 anti-communist purge in Indonesia in which at least half a million, and maybe even more than a million, people died? It’s a question the capitalist world could barely be troubled to ask at the time. After the failure of an alleged coup attempt by the Indonesian Communist Party (PKI) – then the third largest in the world – Sukarno, the fiercely anti-colonialist president, was shunted aside in favour of Suharto. A firm ally of the West who reset the country’s economy with a team of Berkeley-trained technocrats, Suharto’s eclipse of Sukarno was seen by many as a crucial moment in the Cold War. Sukarno had relied on the PKI for support: now communism was banned in South-East Asia’s largest state, with the party virtually eliminated. Once the horrific facts became more widely known, however, the massacres and the grotesquely cruel way in which many of the killings were carried out became one of the worst charges against Suharto’s 32-year rule. No wonder that the US, the UK and Australia have all denied any complicity with the mass murders. Unfortunately, evidence keeps seeping out that the three countries were deeply involved and were more than happy to see suspected communists disposed of, by whatever means. It has been known for years that the American embassy in Jakarta handed over a list of communists for Suharto’s armed forces to locate and eliminate. The latest revelations, secured from the UK’s National Archives by Paul Lashmar, an investigative journalist and academic, show that British officials were running a black propaganda campaign aiming to whip up hatred of the PKI in Indonesia, justifying the murders of ethnic Chinese Indonesians (on the grounds that they were supposedly loyal to “Red China”), and calling for the murder of Subandrio, Sukarno’s then foreign minister. The officials produced newsletters, purportedly written by concerned Indonesians, that they sent to leading anti-communists. In the 25th edition, which Lashmar and his colleagues Nicholas Gilby and James Oliver have shared with me, the author wrote that one answer “to the problems of Indonesia… is to destroy Subandrio and his clique. “The time will come – it must come – when that bird [Subandrio] which has done so much to foul our nest will have its neck wrung; and the whole of Indonesia will rejoice.” The attempted coup, which may very well have been a false flag operation organised by Suharto, would have “left the way open for the Peking-controlled PKI to seize power". Perhaps the worst, considering this was written by employees of the UK Foreign Office, was this: “While we may deplore the unbridled fury which has been unleashed against the Chinese, we realise that for the most part they only have themselves to blame.” Lashmar has been asking UK Foreign Office officials from the relevant time about this over the past 25 years. “They categorically denied they’d done anything wrong,” he tells me. “They hid all of this. Now we’ve got the proof. It’s on the public record.” In 2015, an independent International People's Tribunal set up in The Hague concluded that "the United States of America, the United Kingdom and Australia were all complicit to differing degrees in the commission of these crimes against humanity". But survivors and their families are still waiting for apologies. Arguably communism was a threat to the West, and Sukarno was certainly a threat to Malaysia, a western-leaning country recently created out of four former British colonies that the Indonesian president wanted to "crush". Neither, however, could possibly justify the reign of terror and the appalling death toll. It is surely high time for the three countries to come clean about their involvement. This is not about pointing the finger of blame at individuals – many of whom will be dead by now – nor at institutions, such as the armed forces. The massacres are still a very sensitive subject in the country, but as they happened nearly 60 years ago, no currently serving officials, officers or politicians can be held responsible. No. The point is that the truth about such events – defining turning points in the lives of newly independent countries – must be known, and especially so if foreign powers intervened in ways that changed the course of those countries' future. While plenty of Americans may know nothing about it, for instance, most Iranians will be all too aware that if the US and the UK had not supported the 1953 overthrow of Mohammad Mossadegh, their then prime minister, the country could well be a modern democracy today. That apart, America, Britain and Australia all aspire to global or regional leadership and assume they have the right to lecture others on matters such as human rights, good governance and transparency. But if they are not willing to be honest about their own records, including their own mistakes and, yes, moral transgressions for which they should feel guilt, they hardly have a leg to stand on. Imagine, by contrast, their condemnation if an Asian country stood accused of denying its complicity in an atrocity. The drip, drip of new pieces of information about the 1965-66 massacres, often reluctantly released, should end. Let the truth be told and admitted in full. And then let the people of Indonesia decide how to deal with this most traumatic period of their history.