The Dead Nation (Romania, dir. Radu Jude) is an extraordinary documentary that maps out Romania's sure and steady slide into nationalism, anti-Semitism, fascism, and the Holocaust. The form and structure make it so extraordinary. It is basically 83 minutes of still photographs (from a photographic studio in a small rural Romanian town, taken between 1938 and 1946) set against readings from the contemporary diary of a local Jewish doctor, interspersed with news broadcasts and state propaganda.

Radu Jude introduced the film at the ICA, saying (to much laughter): 'If maybe you think after the first 15 minutes that the film is bad, perhaps you'd better leave because it doesn't get any better.'

The severity of the form is daring. To use moving pictures to display only still pictures is subversive but the interplay between image and words is immensely creative, maybe even dialectical in the way it makes the audience fuse different perceptions, different events, to try and understand or at least confront the barbarity that is described but never seen.

While 'innocent' photographs of family gatherings, rites de passage, holiday snaps, and youths posing in their newfound militias and organisations pass by we hear the words of Doctor Emil Dorian. His diary recounts the surefooted spread and growth of authoritarian laws; sentimental and aggressive chauvinism; fascist organisations; anti-Semitic fantasies; pogroms; massacres; newspaper stories about Nazi experiments with Zyklon-B; the burning and enucleation of Jewish women and children: the horror and despair are relentless, if purely (thank God) verbal and not visual.

And they expose just how much was known, how much was common knowledge, by the population of Romania and the wider world.

In between these calm forensic passages from Doctor Dorian we hear the all-too-familiar broadcasts from right-wing outlets braying about the virtues of nation, folk, heartland, identity, purity, the parasitic Other, the need for strength and optimism! All the toxic effluent that is currently swamping public discourse in the UK and is gathering in poisonous pools across Europe and beyond.

The Dead Nation feels painfully relevant and is unflinching in its steady, sober warning of how a nation, how a political space, can swiftly deteriorate into barbarism while the majority population stand by, look on, continue, mark their special occasions, sleepwalk into Hell.

There is a moment of relief and triumph when Romania finally switches allegiance to the Allied forces. But the moment is brief. The film ends with Stalin. Thinking back to the dysfunctional parents of Ana, Mon Amour it feels like a wonder that anyone survived these traumatic years intact.

Up next: The Party.