In the autumn of 1988, at the Sheraton Hotel in San Salvador, I found myself having a drink with garrulous men in polo shirts. They were from Arena, the party of the Salvadorean oligarchy: coffee-estate proprietors, landowners and former officers who looked to the army and the licensed death squads to protect them from revolution. About that time, Arena was trying to become slightly more respectable. But only a few minutes earlier, its annual convention in the Sheraton ballroom had ended with a cameo appearance by Roberto d'Aubuisson, founder of the party, consummate assassin and organiser of the death squads. Slouching on to the stage in jeans and cowboy boots, like the Fonz in Happy Days, "Major Bob" provoked passionate cheers from the oligarchs' wives, for whom he was the sex symbol of terror. When the excitement had faded, a little party of Arena foot-soldiers carried flags and banners in a goose-step down the hallway as the crowd sang the party anthem, ending with the chant "Fatherland, yes; communism, no". In the bar afterwards, the delegates were drinking Johnny Walker and gin and tonic. The talk turned to London. One of them said: "Ah, London! We love London! Next month, we will go there: to the opera, to Oxford Street and Piccadilly."
I was reminded of this when Andy Beckett, in this wonderful book, described how the great-niece of the 19th-century British tycoon John North - who once practically controlled northern Chile - reminisced about life in Chile after Salvador Allende became the world's first elected Marxist president in 1970. "At the Prince of Wales Club," she said of Santiago in the pre-Pinochet years, "everyone was brown-skinned and black-haired and trying so hard to be English." The Latin American rich might fly to Miami to deposit their dollars and shop for stereos, but Britain, specifically the London of grand hotels, theatres and Fortnum & Mason, is where many of them look to burnish their thin veneer of civilised aspiration.
Throughout Augusto Pinochet's detention in London, his well-spoken, Anglophile supporters traded on their apparent urbanity. But crudity was never far below the surface: when one of the court decisions went against their man, men and women who had been flaunting their impeccable English manners before a BBC crew in Santiago turned and attacked them with a savage class fury.
Beckett pursues more than just this thwarted sense of identification between the Chilean upper class and their ideal of England. He uses Pinochet's arrest in London to explore the historical relationship between Britain and Chile, dating back to the influence exercised by British entrepreneurs and mercenaries in the 19th century. He is skilled at connecting the past and present, thrillingly recreating the lingering traces of history through acute observation and description. As he changes trains in Hastings on his way to meet North's great-niece, the faded station reminds him of Iquique, the town where North built his fortune, and where the shell of the old Victorian train station still stands. On a visit to the port of ValparaIso in 1999, a noisy rally for the Communist Party candidate in the presidential election gives him a hint of what it must have been like to have been on the streets during the Allende years.
Beckett writes vividly about political activists of the Allende era without the condescension of hindsight. There are character portraits of Dick Barbor-Might, a melancholy British follower of Allende for ever marked by his time in Chile; of Sergio Rueda, a clandestine revolutionary tortured by Pinochet's secret police, who has lived in a small terraced house in Coventry for more than 20 years; and also of the mercenary Scottish admiral Thomas Cochrane, who took command of the Chilean navy in 1818, as well as John North, who took over the nitrate mines in the Atacama Desert.
In one of his most successful chapters, he reanimates the forgotten protest by the Scottish Rolls-Royce workers who, in the mid-1970s, refused to service engines from the Hawker Hunter planes that had bombarded the presidential palace in Santiago during the coup in 1973. He is equally good on how some British right-wingers made their own political pilgrimage during the Pinochet era. For instance, he goes to meet Sir Alan Walters, Margaret Thatcher's monetarist guru, who remembers the excitement of his visits to Pinochet's Chile of the 1980s, "the great experiment in liberal economics".
Beckett compares the right-wing distaste for Labour in Britain of the 1970s to the fear of Allende in Chile that brought the truck-drivers out on strike and made the wealthy housewives bang on their empty pots. But the suggestion that a Pinochet could have emerged in Britain is not convincing. The air of truculence may have been similar, but the cast of British characters agitating for a coup against Harold Wilson remains watery and peripheral.
The key absence from Beckett's analysis is the United States, which by the early 1970s was capable of subordinating both Chile and Britain simultaneously, if necessary. Pinochet may have lent his country to the west as a testing ground for monetarism, and Thatcher and her acolytes may have admired him hugely, but it is simply wrong to regard him as the Iron Lady's primary mentor. However, the odd misreading or exaggeration scarcely matters in what is, after all, a hugely enjoyable book.
Maurice Walsh is a former BBC South America correspondent based in Chile