In May 2014, at the height of the civil war in Ukraine, a fire broke out in Odessa’s Palace of All Trade Unions. Dozens of people died and within hours a new battle had begun over who was to blame, as Russia’s army of information warriors spread stories and images online and through state-owned media that pinned the responsibility on Ukraine’s revolutionaries.

“War used to be about capturing territory and planting flags,” observes Peter Pomerantsev in his beautifully written, carefully reported and quietly frightening new book. But what was happening in Ukraine was an early example of something different – the information battle was becoming just as important, some times more so, than the actual fighting.

In Odessa, a group of citizens launched their own investigation, which established the truth. Not that it made a difference – hardly anyone was interested. “Everyone lives in their own reality, everyone has their own truth,” said Tatyana Gerasimova, one of the organisers of the investigation. As Pomerantsev puts it: “Faced with wildly conflicting versions of reality, people selected the one that suited them.”

Part memoir, part investigation, part cry for help, This Is Not Propaganda tours the world and delves into archives, telling the stories of the new information wars, interwoven with passages about Pomerantsev’s parents’ lives. Igor and Lina were Soviet dissidents, harassed by the KGB and eventually deported, for “the simple right to read, to write, to listen to what they chose and to say what they wanted”.

Once the Facebook groups had all grown to about 100,000 members, the internet marketing expert started to post one local crime story each day

Those rights now exist almost everywhere, but more information has not necessarily meant more freedom. While autocratic regimes once controlled the narrative by silencing opponents, they now seek to confuse their populations by bombarding them with false information, half truths and competing narratives. It’s a strategy that Pomerantsev describes as “censorship through noise”, or as one of his interviewees, law professor Tim Wu, puts it, states have moved from “an ideology of information scarcity to one of information abundance”.He meets jaded employees of Russian troll farms using social media to disrupt US elections, Serbian democracy activists training human rights defenders around the world, and government operatives and far-right activists – some of whom have copied the tactics used by pro-democracy campaigners. These tactics are often shockingly simple. In the Philippines he meets “P”, an internet marketing expert who worked on Rodrigo Duterte’s election campaign. P set up a series of local Facebook groups, each focused on local events and news. Once they had all grown to about 100,000 members, he started to post one local crime story each day. Underneath each story his staff – posing as ordinary people – would post comments linking the crime to drugs. P steadily increased the number of crime stories. Soon enough, drug crime became a key election topic.

Facebook Twitter Pinterest Rule of the strongman … the Philippines president Rodrigo Duterte poses with a rifle. Photograph: Bullit Marquez/AP

But this is not just a tale about the rule of strongmen and those fighting back. The new information war is being fought online, particularly on social media, in democracies like ours, too. “I can see people I have known my whole life slipping away from me on social media,” Pomerantsev says, “reposting conspiracies from sources I have never heard of.”

He cites a study of 54m comments in various Facebook groups, by Dr Walter Quattrociocchi of the University of Venice, which found that the longer a discussion continued, the more extreme people’s comments became. Social media, Pomerantsev says, “is a sort of mini-narcissism engine that can never quite be satisfied, leading us to take up more radical positions to get more attention.” The accuracy of those positions is irrelevant, because it’s not about winning an argument: “You just want to get the most attention possible from like-minded people.” This has consequences, beyond the boosting of one’s ego. “Social media drives more polarised behaviour, which leads to demands for more sensationalised content, or plain lies.”

Still, the link between disinformation and the rise of autocracy is clear. One theme that links the new age of populists is nostalgia, or as the philologist Svetlana Boym describes it, “restorative nostalgia”, which strives to rebuild lost homelands with “paranoiac determination”. “The last things desired by those who purvey these phantom, fabricated pasts,” Pomeranstev says, “are facts.” Conspiracy is a way to maintain control, he argues. Everyone’s motives are questioned, no one can be trusted. Newspapers, politicians, judges, experts. All have agendas, all are biased. What, then, is the inevitable solution? “In this murk it becomes best to rely on a strong hand to guide you.”

This Is Not Propaganda is an exploration of the wreckage of liberal democracy and a search for the signs of its revival. What can save us? Reading, for a start. In Beijing, Pomeranstev meets Angela Wu, who researches emerging technology and cultural change at New York University. She travelled across China interviewing readers of a blogging site called Bullog, which was home to opposition voices. Its readers came from a range of backgrounds, but one thing many of them had in common, Wu discovered, was that they had been voracious readers from a young age. As Pomeranstev puts it: “The more creative the literature you read, the more you would be able to imagine a different reality to the one around you.” That is something that had helped Igor, too.

The disinformation age: a revolution in propaganda Read more

The book does not prescribe policy solutions, but that’s fine. Before we work out what we’re going to do, we need to understand the scale of the problem – which Pomerantsev sets out with the right mix of alarm and detail. Many of us in the west show arrogance and ignorance if we believe what happens elsewhere cannot happen here. Our democracy is stronger than that of the Philippines. Our media are more independent than Russia’s. Our institutions have existed longer than Estonia’s. There is a danger that this complacency may lead us to believe Facebook ads cannot influence our democracy, that politicians cannot manipulate our media, and that someone whose career has been one long information war of lies and half-truths, jokes and smears could never take power in our country.

• Steve Bloomfield is deputy editor of Prospect. This Is Not Propaganda: Adventures in the War Against Reality by Peter Pomerantsev is published by Faber (£14.99). To order a copy go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £15, online orders only. Phone orders min p&p of £1.99.