“He who controls the past controls the future. He who controls the ­present controls the past.”

Recent events made me think of these words by George Orwell, the novelist who had such insight into the methods of totalitarian governments.

Within hours of Nelson Mandela’s death, the South African Communist Party (SACP) at last admitted what I and some other historians had discovered through patient research – namely, that Mandela was at the time of his arrest in 1962 a member not only of the party, but also of its central committee.

It is astonishing that so many people lied about this for so long. Maybe the SACP’s chieftains will now admit that the ANC’s key statement of principles, the 1955 Freedom Charter, was written by white communists.

The suppression of knowledge about South Africa’s past goes far beyond these two examples. Three years ago, while I was researching my book External Mission, I was astonished to order files from a public archive and to find them empty.

I asked the archivist what had happened. Some ANC heavies had taken away the papers, he told me.

Many historians in South Africa have stories like this. The National Archives in Pretoria has become notorious for its inability to transmit public records for study. Various SACP and ANC archives mysteriously appear and then disappear.

The Nelson Mandela Centre of Memory seems to have been active in suppressing public discussion.

All of this matters because, as Orwell understood after experiencing communist manipulation during the Spanish Civil War, controlling the past is a vital technique of totalitarian government.

Successive ANC governments have done everything to burnish the myth of the armed struggle, which was always more theatrical than real.

The ANC insists that the South African Defence Force was smashed at the 1987-1988 battle of Cuito Cuanavale in Angola, when this is blatantly untrue. A generation of South Africans has been told that the ANC single-handedly brought about the downfall of apartheid, when the truth is that it was the work of many other actors in society, not to mention the ending of the Cold War.

There is no space for the younger generation to learn about black consciousness. There is not even any room to debate apartheid properly, which has to be kept as a monolithic evil in contrast to which the ANC can underline its own claim to legitimacy.

The point is to cut off the possibilities of clear thinking for anyone who wonders what sort of country South Africa really is and what sort of government it has.

For these reasons, those South Africans who think “so what?” when they learn that Nelson Mandela was an SACP member are wrong. They need to understand that the armed struggle was originally the work of the SACP, decided at a conference in Emmarentia in December 1960 that was attended by just 25 people. Mandela was one of the few black people present.

The ANC as an organisation in fact never voted in favour of armed struggle. Mandela was given the task of persuading the sceptical ANC president, Albert Luthuli, to accept the policy retrospectively. Luthuli refused, but he conceded that he could tolerate the military organisation Umkhonto weSizwe if it was entirely separate from the ANC.

As the ANC’s grip on historical memory loosens, rethinking the past becomes a politically explosive activity. I have lost count of the times that radical, angry young black South Africans have asked me why the transition from apartheid left so much of the country’s wealth in the hands of whites. Many Afrikaners wonder how, from a position of strength and in control of a proudly undefeated defence force, the National Party managed to give so much away in such a short time.

What was the real nature of the violence in the transitional period? If it wasn’t all the work of a mysterious third force, where did it come from?

Maybe the public humiliation of President Jacob Zuma by the crowd who booed him at Mandela’s memorial service will be the starting point for the more extensive debates that are necessary if we are to see a more healthy politics emerge.

“Officially invented history always prepares its own destruction,” the late Frederik van Zyl Slabbert wrote. “The burden of the lie becomes too great to bear.”

This moment of truth may now be coming to South Africa.

Stephen Ellis works at the ­Afrika-Studiecentrum, Leiden, the ­Netherlands. His book, ­External Mission: The ANC in Exile, ­1960-1990, is published by Jonathan Ball.