Does political cinema mirror life? How much impact can a movie have on its audience? To what extent is it able to influence the way we think about politics? The relationship between cinema and politics, often troubled, has recently become far too distant.
Last month, an issue of the International Herald Tribune featured two unrelated articles about the French riots. One argued that films have long been warning that French-born Arab and black youths feel alienated and that the urban environments in which they live are ripe for explosion. The "banlieue" genre, dating back to the mid-1990s (and including films such as La Haine), has been more effective in highlighting the problem than the conventional media. Yet politicians have failed to take notice - as was shown by the other article, which reported a French parliamentary debate on strengthening anti-terror laws through increased investment in high-tech surveillance. The gulf between politics and cinema could hardly be greater. What a tragedy that politicians seem to find it all but impossible to take note of life as reflected in art.
I've always believed that cinema can be a powerful force in creating (or reflecting) an appetite for change. It has tremendous power to engage and inspire - far more than television, which has a different relationship with its viewer.
Take the role of the Hollywood movies of the late 1950s in getting white Americans to understand the unsustainability of their racial attitudes. More than any other medium, it was cinema that established the environment which led to Kennedy's election and the civil rights legislation brought in by his successor. Now George Clooney's wonderful Good Night, and Good Luck offers a media-obsessed generation the opportunity to reflect on exactly why television and good journalism remain important.
In Britain, back in the 1940s, movies were actively used by the government as a vehicle for political propaganda. I have recently been making a series of programmes for BBC Radio 4 about the changing political role of British cinema. I focus on three films from the mid-1940s to the early 1990s.
The first is the wartime documentary A Diary for Timothy, made by Humphrey Jennings, a brilliant film-maker who inspired a generation of cinema audiences with his uplifting images of wartime life. Jennings's films, which were made for the Central Office of Information, were shown to a mass audience as B-movies attached to the main feature, at a time when everyone went to the cinema. A Diary for Timothy takes the form of a diary to a baby born six months before the end of the war. It acted as a kind of "cinematic manifesto" for the type of society people yearned for after six years of crisis, in effect heralding the wel- fare state. Written by E M Forster and narrated by Michael Redgrave, the film has been described as "the script of the new governing class". Jennings, a pre-war Oxbridge graduate, was part of a generation that, as a result of its wartime experience, came to admire the British working class, and that respect shines through in his work.
Although propagandist in nature, A Diary for Timothy struck a chord with a nation trying to pull together in building a better society. Many scenes are incredibly powerful - such as the one in which Timothy, gently blow-ing bubbles in his cot, is asked: "Will you have to suffer money and greed ousting decency, or will you make the world a different place, you and all the other babies?"
Jennings's dream had clearly begun to sour by the late 1950s, when the Boulting Brothers made their comedy I'm All Right Jack, starring Peter Sellers as the bolshie shop steward Fred Kite. It was a remarkably brave movie - one of the first to tackle the controversial subject of labour relations, made all the more sensitive because of the fraught relationship that existed between management and unions in the film industry.
I'm All Right Jack defined an era, reflecting a nation uneasy about its economic underperformance and the increasingly apparent stresses on the welfare state. It brilliantly sends up the demarcation disputes of the 1950s, which were something of a low point in British industrial relations. One of the central characters, Stanley, new to the shop floor, ends up with a flat battery on his machine but is told no one else can plug in his equipment, because one man mustn't do the work of another. "Demarcation, Stan," as his fellow workers patiently explain.
The phrase "I'm all right, Jack" quickly became shorthand for union-bashing, and the film undoubtedly damaged the perception of the unions. Yet it is management who are the real villains - they are positively corrupt, whereas the workers are just lazy. However, the anti-union message stuck because it chimed with the mood of the times, particularly as reflected by large elements of the press.
Thirty years later, the good-humoured social comment of I'm All Right Jack gave way to something more disturbing. Ken Loach's Hidden Agenda is loosely based on the investigation by John Stalker into shoot-to-kill allegations against the security forces in Northern Ireland, and on the allegations of a plot by rogue elements in the intelligence services to destabilise Harold Wilson. When the film came out it caused a political storm and was condemned as IRA propaganda that blurred fact and fiction. In subsequent years, however, some people have changed their views. John (now Lord) Stevens, the former Metropolitan Police commissioner, who was sent to Northern Ireland in the wake of the collapsed Stalker inquiry, told me he found the scenes relating to Stalker very realistic. May Blood, another colleague in the House of Lords, who comes from the Northern Irish Protestant community, told me that when the film first came out, she and many like her thought it was "just a piece of nonsense, but with hindsight there's a lot of truth in it".
One of the sternest critics of the scenes relating to Northern Ireland is Bernard (now Lord) Donoughue, a former aide to Harold Wilson. But even he now accepts that the account of plots against Wilson had some basis in reality, saying "there were rogue elements in the security services", as well as "others on the right wing of the Conservative Party who showed sympathy for a coup".
Whether or not you agree with Loach's analysis, there's no doubt that films such as this can play a crucial role in generating a better-informed, more lively political and social debate. For years, stories that tackled controversial and complex issues were second nature to film-makers. Sadly, that is becoming increasingly rare. My reason for wanting to make the radio series was to convince myself that cinema still has an important role to play in exploring society's truths - as well as its myths.
We need to convince a whole new generation of film-makers that this is a challenge worth accepting. And we need to convince politicians that, from time to time, they should heed the message.
David Puttnam's three-part series for BBC Radio 4, Movies With a Message, starts on Sunday 1 January at 10.45pm, with repeats the following Wednesday from 8.45pm