'We live in a strange time …' murmurs Adam Curtis at the very beginning of his latest masterfully built but contentiously structured foray into the accumulated BBC footage archive from around the world. His voice is soothing and professorial, as though he were the David Attenborough of ripe political conspiracy theorising. In the first few seconds of this 165-minute opus, faces gaze, enraptured, to a glowing strobe in the ceiling, a bomb goes off and the camera falls to the floor, and Curtis reels off his latest targets: 'suicide bombs, waves of immigrants, Donald Trump, Vladimir Putin, even Brexit . . this film will tell how we got to this strange place.'

This place, as is usually the case with Curtis' films, is one where everybody in power knows everything and nobody's telling the people; where backroom political decisions, old grudges and psychological theories fester over the years into a network of connected domino pieces which illustrate the structures of power which we're not meant to know of. In Curtis' world, the bankruptcy of New York in the 1970s feeds into banks edging into a position of political control in order to bail it out, which feeds into Donald Trump's rise as he builds opulent buildings in the remains of the decrepit city. Meanwhile Henry Kissinger's Cold War attempts to divide and control the Middle East alienate Syria's ruler Hafez al-Assad (father of the current President, Bashar; one of the more mundane revelations is that the latter's favourite band is Electric Light Orchestra) and eventually give rise to Colonel Gaddafi's emergence as a 'fake terrorist mastermind'.

And so it goes, through an admittedly thrilling and often terrifying two and three quarter hours of relentless questioning. Typically, Curtis' visual and audio scene-setting is hugely engaging, cutting away to warzone reporters addressing cameras as bombs go off behind them, or pre-2001 clips of landmark American buildings being destroyed in Hollywood movies cut into a hallucinatory montage to the soundtrack of Suicide's 'Dream Baby Dream'.

The major events of the last four decades are covered; a catalogue of wars in the Middle East, the fall of Communism, the rise of cyberspace, 9/11, the crash of 2008, the Arab Spring, Occupy Wall Street, Brexit, the rise of Trump all to build a case that, apparently, nobody knows anything. Which is an easy get-out when you're making a documentary, frankly. Taking the temperature online of people's expectations for Curtis' latest, it's possible to detect a certain weariness, even among fans. In an age where it's frankly painfully obvious that nobody knows anything, what's required are answers; what Curtis offers is the pretence of answers.

His greatest strengths are also his greatest weaknesses, as the purposeful cut and thrust of his editing lends the impression that connections exist where there are none. The control desk for the drone which took out Gaddafi's escaping car and the server where footage of his murder was uploaded to the internet are less than ten miles apart in the desert outside Las Vegas. 'Wow,' you think. And then you think again, and you realise it doesn't matter. You realise that Trump and Assad have nothing to do with one another, really. Or Brexit and Henry Kissinger. When Curtis discusses Putin's mercurial strategist Vladislav Surkov, or the uncanny way Trump can inspire devotion by holding literally opposite opinions at the same time, one might be forgiven for detecting a note of admiration at their psychological skill.

Yet despite such reservations, Curtis' work is still strangely brilliant. Certain scenes are heart-stopping: the fearsome, tattooed Trump supporter declaring himself 'a proud fuckin' American, made in the USA, bitch!'; the tearful woman fearful of the rise of fascism at the film's climax; all the warzones and corpses and glimpses of harrowing human drama. This is not a secret history, as it presents itself, but it is a history, or rather multiple histories seen in long-buried detail. Narrative is key: the narrative governments create, dictators, rebels, movements, artists, even just the story we build of the world from our own internet bubbles, most of them demonstrably not part of some long game decades in the making. Curtis is just one more storyteller, with his own sources and his own perspectives. As a documentarian, a journalist, he's as open to question as any. As a dramatist, however, he's truly formidable.

HyperNormalisation is available on BBC iPlayer from 9pm on Sun 16 Oct.