The man South Africans know as ‘Prime Evil’ has just been released on parole. Eugene de Kock ran a secret death squad for the apartheid government during the dying years of white minority rule. His job was to capture liberation movement soldiers, torture them into betraying their comrades, and then train them as professional killers. They were known as ‘askaris’ and their nasty re-education took place on a farm in the north of the country called Vlakplaas, which means, simply, ‘shallow farm.’ How many people they tortured, maimed and killed is unknown, but it ran into the hundreds. De Kock has been behind bars since 1996. He is the ultimate symbol of the evil of the old order and he is now free and in the world. What might this mean for South Africans?

Those looking for a searching, if uncomfortable guide to how to answer this question ought to read a book called Askari by the South African historian Jacob Dlamini. Askari is about a man who worked for De Kock at Vlakplaas. Glory Sedibe, a senior figure in Umkhonto we Sizwe, the armed wing of Mandela’s African National Congress (ANC) was kidnapped by apartheid agents from a police station in Swaziland, tortured and turned. Like other askaris, he proved his loyalty to De Kock by betraying his erstwhile comrades, giving away vital information, testifying in court as a state witness, and possibly participating in torture and killing. Dlamini tells us that although Sedibe became an askari against his will, he came to enjoy it.

The narrowest purpose of Askari is simply to ask why Sedibe did what he did. But Dlamini has bolder ambitions. Using Sedibe’s story, the book evolves into an investigation of the moral lives of oppressed people and the story it tells is in this regard is bravely complex. Between black and white South Africans, Dlamini argues, was a “fatal intimacy”. While constrained by circumstance, black South Africans always faced a wide and complicated filigree of choices about how to relate to their oppressors, many of them morally uncomfortable. Some of the ways in which a black person might collaborate with the regime were subtle, often invisible. Indeed, many collaborated “under the cover of racial solidarity”, using their black skins to conceal what they were doing. Sedibe, Dlamini argues, occupied one positon along a spectrum of betrayal and deceit. He faced choices many ordinary black South Africans faced and was thus, in a sense, ordinary. It is a startling and powerful argument, one that required of its author enormous reserves of intellectual steel.

Askari is about recent history, not the present. Nonetheless, the imagination of any historian is fired, at least in part, by what is happening around him, and I think that we can only understand the full import of Askari with reference to here and now. Towards the end of Askari, Dlamini shares a childhood memory. He is on a bus with his mother somewhere in the old apartheid Bantustan of the Transkei. It is the heart of winter. The bus is stopped at a police roadblock and a man boards. He is wearing a full length trench coat, his face concealed by a balaclava. Accompanied by two police officers, he walks slowly down the isle, shining a torch into the face of each passenger. Every so often, he demands of a passenger his pass book, an identity document black South Africans were required by law to carry at all times. He disembarks and vanishes. The bus drives on.

The memory is now 30 years old, but it still haunts Dlamini. Who was this man? Was he an askari? Dlamini and his mother were at the time en route to a famous faith healer called Msamariya. They had travelled half way across the country to see her. Dlamini notes that in his later years, Sedibe, too, was in search of new faith and was on the brink of joining the Zionist Christian Church when he died. And so there you have it. Sedibe is familiar. He is a black South African, just like Dlamini. And, like Dlamini’s mother, he searches for spiritual healing. And yet he wears a mask. Beneath the signs of the ordinary, you cannot know what a person has done. This theme of dark hinterlands concealed by the familiar pervades Askari and it is hard to avoid wondering whether Dlamini was motivated to write this book by his sense of South Africa here and now. Across the civil service, in cabinet and in the legislature are people with pasts. What exactly did they do thirty years ago? Dlamini is not suggesting a witch hunt. Nor is he saying that black and white people are equally responsible for what happened during apartheid. Quietly, but forcefully, he is suggesting something much more subtle.

It would be a mistake, he is saying, to locate all the evil of our past in men like De Kock. To do that would be to let those who govern SA now off the hook, to say that they do not have to give moral accounts of themselves because they were always on the side of the angels. He is saying that South Africa’s Truth and Reconciliation Commission erred when it divided those who peopled the past into victims and perpetrators because many were both. Acknowledging this matters, Dlamini is saying, because if we understand that nobody is on the side of the angels, we know, too, that everybody must account. Askari is an extraordinarily brave book. It ventures onto treacherous terrain, daring to say things so delicate and so easily misunderstood. It could not possibly have been written by a white person. And it took a black person with courage and poise to pen it. I think that it is the best guide we have to understanding what it means that De Kock is free and among the South Africans he did so much to hurt.