London, United Kingdom - From coins bearing images of ancient Greek monarchs, via world wars and clashes of ideology to our modern obsession with social media, an ambitious new exhibition at the British Library is attempting to expose how states have used propaganda to exert influence over our lives and behaviour.
Although typically the term has had a negative connotation, Propaganda: Power and Persuasion broadens its definition of the word to include anything used by governments as a means of validating and justifying their actions, building support and influencing behaviour.
It also aims to challenge the depiction of propaganda as a blunt weapon in the arsenal of Orwellian "ministries of information", arguing that it is at its most effective when it is altogether more discreet.
"People still associate propaganda with lies and falsehood, as something to be avoided at all costs and a cancer on the body politic. I think this misunderstands the basic nature of the concept," said David Welch, professor of history at the University of Kent and author of a forthcoming book to accompany the exhibition.
People still associate propaganda with lies and falsehood... I think this misunderstands the basic nature of the concept
"The preoccupation with lies and falsehoods misses the basic concept that it is ethically neutral."
Still, many of the most eye-catching exhibits on display nod towards the traditional idea of propaganda as something deployed to drum up support by totalitarian and revolutionary states or nations at war.
As well as famous recruitment posters from the two world wars and examples of Nazi and Soviet imagery, there is a two-metre portrait of Napoleon in full imperial splendour, and a Cultural Revolution-era image of a young Mao Zedong that is believed to be the world's most reproduced painting, with more than 900 million copies made.
Among Cold War imagery bleak with paranoia and menace, there is a cheery futility about the US "Duck and Cover" civil defence film from the 1950s, in which Bert the Turtle tells schoolchildren to shelter under their desks in the event of an atomic attack, while a British leaflet on protecting your home from thermonuclear assault helpfully advises "Read this with care and keep it handy".
Yet a section on public health demonstrates how the same style of bold artwork and memorable slogans used in wartime posters were put to use in western democracies with the benign purpose of improving living standards and wellbeing.
"One of the things we are trying to get across is that it is not necessarily the case of an all-powerful state directing the thought of a malleable public mind," Ian Cooke, co-curator of the exhibition, told Al Jazeera.
"It is often the other way round; that you start with the challenge of how you convince people that what you are doing is legitimate and credible and in their interests. There is an idea that, when you move into a democracy, propaganda has to get more sophisticated."
The exhibition, which runs until September 17, also examines how propaganda has been used for longer-term and less tangible goals such as nation-building and shaping and reinforcing social values over generations.
Any Briton gazing at the 1789 commemorative fan celebrating George III's recovery from illness with the words "Health is restored to ONE and happiness to millions" would recognise a state-sponsored ideal of monarchy still resonant in last year's celebrations marking Queen Elizabeth II's Diamond Jubilee.
"We've looked at some of the things, such as symbols, flags and ceremonies, that society has used to create those norms and values and a sense of belonging and continuity. It is about how you create a society," Jude England, the British Library's head of social sciences, told Al Jazeera.
Yet one of the most compelling sections examines something closer in spirit to traditional propaganda: the British government's use of information as it sought to make a case for war in Iraq - based on what has now been exposed as mistaken and misleading intelligence about Saddam Hussein's purported weapons of mass destruction programme.
A complicit media
In an interview for the exhibition, Alistair Campbell, then-prime minister Tony Blair's communications chief, appears almost to be playing to caricature when he complains: "I think the whole concept of propaganda, spin and all the rest of it has been defined very negatively."
And he reveals a great deal about the mindset among key decision makers in the British government in the leadup to war, as he explains how the 1999 campaign in Kosovo had put "iron in his soul" because of frustration at how "our media" had bestowed "moral equivalence on a nasty little dictatorship".
For Campbell's critics, such as the veteran investigative journalist John Pilger, the sort of media manipulation he describes offers an insight into a form of influence far more pervasive than conventional propaganda.
"We often think of propaganda in terms of its very vivid, infamous iconography - such as Nazi propaganda, Stalinist propaganda - but really the most powerful propaganda is insidious, something that we often don't recognise, something disguised and it comes from two words: public relations," said Pilger.
For those on both sides of that argument however, the landscape in which propaganda, spin and PR are deployed may be shifting in ways that create a whole new set of questions and problems.
The final room of the exhibition is dominated by a data installation examining the extraordinary power of social media to shape public opinion and our own complicity in the process.
If we turn on the news now and we look at its sources, we will find it is taking at face value what it is told by the state, by vested interests and by people of importance and authority. That is probably the main source of what I would call modern insidious propaganda.
In real time it shows how Barack Obama's "Four more years" tweet, issued by the president's campaign in the moments after his 2012 re-election was confirmed, became the most retweeted message in history.
On the one hand, it seems to suggest, the means of propaganda have been democratised. Anybody who has posted a tweet or updated their status has attempted in some way to shape the perceptions of friends and followers. And yet, in the echo chamber of social media, perhaps we also risk being manipulated by an invisible hand, or falling prey to groupthink.
In such circumstances, the integrity and functioning of traditional media - both in filtering significant and reliable information against an ever-louder clamour of social media and in holding authority to account - has perhaps never been as crucial, nor more difficult to achieve.
"What the news media is trying to do is make sense of all this noise and make sense of what is happening," said Cooke.
"But the challenge is, because of the pressure to get stuff out at near to the same speed as social networks, that it gets far more difficult to do the things that you would want people to do, which is to check authority and credibility."
For Pilger, that is a trend with worrying repercussions - both for the media and society at large.
"The essential role of a free media is to call authority and power and government to account, and the propaganda we are discussing almost succeeds by default because this vital element is left out," he said.
"If we turn on the news now and we look at its sources, we will find it is taking at face value what it is told by the state, by vested interests and by people of importance and authority. That is probably the main source of what I would call modern insidious propaganda."
Follow Simon Hooper on Twitter: @HooperAJ