Two spies meet in a white-tiled bathroom in Tehran. One large chap is perched on a creaking laundry basket, while his host, seated on the toilet, pours good-quality vodka into a pair of glasses. Water gushing from the taps and the radio playing prevents any officers of the Islamic Revolutionary Guard who might have bugged the place from overhearing their conversation. It is 1981, two years after the Iranian revolution, when ‘the world’s oldest empire folded and plummeted like a kite in a hurricane’, Macintyre tells us in true Bond-baddie style. Then comes an astounding confession, words that Bond has never uttered, and ‘by the time it took to run a bath, the KGB spy had become a double agent’. It’s the perfect meet-cute to set up the action, the context and the preoccupations that drive this enjoyable caper.

Enter a disaffected spook, a few hardline clerics, many bloodthirsty terrorists and a lot of weaponry

At the height of the Cold War, Iran was a crucial intelligence battleground between East and West. In 1978, as the British embassy in Tehran was still holding tea parties, the Iranian revolution began to erupt with cataclysmic speed and brutality. MI6, the CIA and the KGB all chose to interpret events through the lens of Cold War politics. Almost overnight the West not only lost access to Iranian oil but feared that this prize might fall to the USSR. Moscow, considering the regime change to be the precursor to communist revolution, quickly increased its support for the Iranian Communist party and, in late 1979, invaded Afghanistan. None of the dominoes fell as expected. As fears of nuclear confrontation soared, the rule of unintended consequences began to assert its authority. Enter a disaffected spook, a few hardline clerics, many bloodthirsty terrorists and a lot of weaponry and you have a recipe for both high drama and the potential end of the world as we know it.

Macintyre does a great job on the 20th-century history of Iran, not ironing out the complexities but smoothing them into comprehensible shape. Tehran comes to life as a city of nightingales and scattered gunfire, where people kill with medieval cruelty one minute and quote poetry the next. Like many of Macintyre’s books, this one also has a colourful cast – here of organ-playing English spies and American ‘cold warriors’, conniving communists, radical religious scholars and the odd stalwart wife who knows how to survive an oppressive regime, having been educated in the English boarding school system. The spotlight, however, is firmly on the rival spies, slowly dancing towards an embrace.

Vladimir Kuzichkin of the KGB had joined what he hoped would be an elite corps of ideological warriors in Tehran, only to find his fellow Russians corrupt, lazy and drunk – they distilled their own vodka in dry post-revolutionary Iran. MI6’s Ian McCredie didn’t arrive until 1981, in the slight thaw after the Iranian coup, when the now hated British embassy was under Swedish protection and only ‘a few diplomats flitted around, like moths in an empty cupboard’. At first these Cold War counterparts are circling, Macintyre writes with a director’s eye, ‘wandering shadows, quite unaware of each other, secretly seeking out the same dark corners of the teeming city’.

Things heat up after the intelligence deal is done. As Macintyre is well aware, the British Secret Services have a long history of double entendres in their codenames and ‘Redwood’ not only reflected the towering physical stature of the mighty Russian agent with access to every secret of Soviet intelligence in Iran, but also a secret of his own. Nothing in McCredie’s life or training had prepared him for the challenge ahead, and the tension builds dramatically as the theocratic regime cracks down and Redwood himself begins to crack up.

As with all good spy stories, there are plenty of twists, turns, desires, betrayals and unexpected outcomes, and a whole second act of the intelligence game. But what makes this tale so engaging is how close we feel to both the key spies and the history at the book’s heart. This story happened less than 50 years ago. Alec Guinness, Frederick Forsyth and even Joanna Lumley feature, and when the new Iranian regime trolls the British embassy through renaming its street address, it feels very like Iran today posting Lego videos to embarrass Donald Trump. Trump also gets a name-check when, as a young Manhattan real estate entrepreneur, he pivots in an interview about the decor for his new tower to asserting that America should have already invaded Iran. ‘That would have been the easiest victory we would ever have won,’ he spouts. Macintyre signed off on this manuscript in March, acknowledging the renewed violent conflict, repression and mutual antagonism between Iran and the West.

‘The Redwood story can be read in sharply contrasting ways,’ he concludes, ‘as triumph or disaster.’ It was of course both. MI6’s management of Redwood was textbook intelligence work and a huge blow to the KGB. But while the second act in the saga may have administered the coup de grâce to Soviet aspirations, and possibly averted nuclear confrontation, it also bolstered a murderous, fundamentalist regime and helped create a monster rogue state that would develop its own nuclear weapons, repress its citizens and become a sponsor of world terrorism.

The Cold War was played out in many arenas but was essentially seen as a binary struggle between ‘red and white’. In Iran there were other ideologies to consider, to which neither Moscow, London nor Washington gave enough attention. In focusing on one remarkable, deeply flawed but courageous individual, Macintyre reminds us that history is not solely written by great powers, however driven or misguided by grand narratives and world views, but also by very personal choices, desires and decisions. In this, Redwood is a triumph.