After 20 years of war, Don McCullin, connoisseur of capturing conflict, has just completed a two-year project photographing nine remote tribes in the valley of the Omo River in Ethiopia.

Amid the modern world’s increasingly insatiable appetite for change, here are a people whose lifestyle has not altered substantially for millennia, where practices such as circumcision, self-mutilation and ritualistic fighting, often to the death, are commonplace.

Ancient tribes adorned with modern weapons makes for an uncomfortable juxtaposition. The people possess an almost defiant dignity, offset by a stillness that lends a mood of quiet eeriness to the images. The pictures are posed and formal, with strikingly sophisticated stances. Compositional simplicity allows us to concentrate on themes of family, community and the relationships that underpin them.

But the simplicity is deceptive. Scratch the surface and there is an undercurrent of violence, of something layered and knotted with tension. It is clear that a wider, more complex narrative exists. We gaze in fascination; they gaze back intrigued and defensive in equal measure.

McCullin acknowledges the violence, rather than revealing it explicitly. No longer on the battlefields, he is documenting something just as edgy: conflict on the brink, proof if it were needed that he has lost neither his edge nor his instinct. He captures perfectly the insecurity of a people caught precariously between the possible erosion of their old life and the escalation of the new.

Prefaced by diary extracts, this stunning book offers a snapshot, albeit through a practised eye, into this remote world and its tribes. “Poverty, guns and murder are poisoning them,” says McCullin, who, as an outsider, sees it clearly. Do the tribes take the same view?          

Frances Anderson