Where are the Martha Gellhorns of today?

A favourite quotation of mine is by the great Irish muckraker, Claud Cockburn: "Never believe anything until it is officially denied." Cockburn might have been referring to Wilfred Burchett, the Australian journalist whose extra-ordinary and often embattled career included what has been described as "the scoop of the century".

A favourite quotation of mine is by the great Irish muckraker, Claud Cockburn: "Never believe anything until it is officially denied." Cockburn might have been referring to Wilfred Burchett, the Australian journalist whose extra-ordinary and often embattled career included what has been described as "the scoop of the century".

While hundreds of correspondents "embedded" with the Allied occupation forces in Japan in 1945 were shepherded to the largely theatrical surrender ceremony, Burchett "slipped the leash", as he wrote, and set out on a perilous journey to a place now engraved in the human consciousness: Hiroshima. He was the first Western journalist to enter Hiroshima after the atomic bombing, and his front-page report in the Daily Express carried the prophetic headline: "I write this as a warning to the world."

The warning was about radiation poisoning, whose existence was denied by the occupation authorities. Without hesitation they denounced Burchett, with other journalists joining in the official propaganda and orchestrated attacks on him. On his own, courageously, he had exposed the hidden horror of the nuclear age.

What Burchett did was to hold great power to account, which is journalism's paramount role. Is that role now lost? Are great mavericks such as Burchett, and Martha Gellhorn, Seymour Hersh, Amira Hass and Paul Foot and Robert Fisk no longer the models for young journalists? Corporatism and consumerism are laying to waste the breeding grounds of free, inquiring journalism when it has never been needed more. Cockburn's cry that officialdom, the state, routinely lies is not what the media courses teach. If they did - and the evidence has never been in greater abundance - the cynicism that many young journalists believe ordains them as journalists would not be directed at their readers, viewers and listeners, but at those in false authority.

While much of journalism falls to the onward march of public relations, and the very concept of "the media" becomes indistinguishable from information control, great, unaccountable power still fears journalists who peer behind façades. Opprobrium from on high is often their badge of honour. When the BBC refused to show James Cameron's filmed report from wartime North Vietnam, Cameron told me: "They whispered I was a dupe, but what really upset them was that I was not their dupe."

In these days of corporate "multi-media" in thrall to profit, many journalists have become absorbed into a propaganda apparatus without consciously realising their true role. There are rewards for their collusion: fame and faint recognition, which some journalists crave: an invitation to participate in a government seminar, even a lowly award from Tony, via the Queen. They are the distinguished spokesmen of the spokesmen, debriefers of the briefers, what the French call fonctionnaires: the truly "embedded".

In his unpublished introduction to Animal Farm, George Orwell described how censorship in free societies was infinitely more sophisticated and thorough than in dictatorships because "unpopular ideas can be silenced and inconvenient facts kept dark, without any need for an official ban". It is more than half a century since he wrote that, and little has changed. This is not to suggest a "conspiracy", which in any case is unnecessary. Journalists and broadcasters are no different from historians and teachers in internalising the priorities and fashions and propriety of established power. Like others with important establishment responsibilities, they are trained, or groomed, to set aside serious doubts. If scepticism is encouraged, it is directed not at the system but at the competence of its managers, at personalities, or at popular attitudes as journalists perceive them. Thus, Tony Blair's detractors call up his "grievous mistakes" but still refer to his "idealism" and "decency", regardless of the thousands of Iraqi deaths his actions have caused. Minimising his culpability is an article of faith; in the way Britain and America deal with the world, only "they" produce war criminals: never "us". From the Murdoch press to the BBC, the undeclared rules of the corporate media club vary not a great deal. The invisible boundaries of "news" allow false premises to become received wisdom and official deceptions to be channelled and amplified. A one-way moral mirror is held up to the fate of whole societies, which are often reported according to their usefulness to "us": the term used for Western power, with its narcissism, dissembling language and good and bad terrorists, worthy and unworthy victims. That the systematic, historic terrorism of states, especially the imperial Western, dwarfs the sporadic terrorism of al-Qa'ida and other sects, is unmentionable. "Normalising the unthinkable" is Edward S Herman's apt description for the role of journalists in the division of labour in a great imperial task like the attacks on Vietnam and Central America and the lies that led to the invasion of Iraq.

In the United States, which constitutionally has the freest media in the world, the suppression of the very notion of universal humanity has become standard practice. Like the Vietnamese and others who have defended their homelands, the Iraqis are unpeople: a mob, tainted, to be abused, tortured, hunted. "For every GI killed," said a prominent letter in the New York Daily News, "20 Iraqis must be executed." The New York Times and The Washington Post might not publish that, but each played a prominent role in promoting the fiction of Saddam Hussein's weapons arsenal. In the run-up to the invasion, neither published a single investigative piece that seriously challenged the lies. Had they, together with the broadcasting companies, done so, and had they exposed Bush's lies, tens of thousands of people might be alive today. Putting aside the honourable exceptions, the same can be said for most of the British media.

There is a surreal silence today, full of the noise of "sound bites" and "grabs" of those with power given opportunities to distract us from their crimes. An exquisitely irrelevant vote in Parliament on fox hunting and a great deal of journalistic indignation about "breaches of security" by fox-hunting zealots were no more than distractions from the horror of Iraq. Never has there been such a volume of repetitive "news" or such an exclusiveness in those controlling it. In 1983, the world's most powerful media were owned by 50 corporations. Rampant de-regulation has ended even a semblance of diversity. In February, Rupert Murdoch predicted that, within three years, there would be just three global media corporations and his empire would be one of them. Perhaps he exaggerated, but not by much. Even on the internet, the leading 20 websites are now owned by the likes of Fox (Murdoch), Disney, AOL Time Warner, Viacom and a clutch of other giants; just 14 companies attract 60 per cent of all the time Americans spend online. Theirs is a global ambition: to produce not informed, free-thinking citizens, but obedient customers.

The mantra that leads us down this road includes something called "competitiveness". Like "democracy" and "reform" and "free market", this does not mean what it says. It is monopoly of ownership, and thought. The Blair government's assault on the BBC is part of this. The BBC's power lies in its dual role as a publicly-owned broadcaster and a multinational business, with revenues of more than $5bn. More Americans watch BBC World than Britons watch the main BBC channel at home. What Murdoch and other ascendant media barons have long wanted is the BBC broken up and privatised and its vast "market share" handed over to them. Like godfathers dividing turf, they are impatient.

The genesis for this is not hard to trace. In 1995, Murdoch flew Tony Blair to Hayman Island off the northern Australian coast. Standing at the News Corp. lectern, the future British PM effused about his "new moral purpose" and pledged safe passage of the media from "heavy-handed regulation" to the "enterprise" of those like his host. The next day, in London, satire died once again when Murdoch's Sun commented: "Mr Blair has vision, he has purpose and he speaks our language on morality and family life."

What do we do? Ignacio Ramonet, Le Monde Diplomatique's director, proposes a "fifth estate" that monitors, analyses and makes a public issue of media mono-news and monoculture. We might look to the emerging samidzat, the word for the unofficial media during the late Soviet period. Given the current technology, the potential is huge.

On the worldwide web, the best "alternative" websites are already read by millions. The courageous reporting of a new breed of freelance journalists and non-journalists, "citizen reporters", is already making itself felt in dangerous places like Iraq. We need a new generation of "honourable exceptions", like Hersh and Fisk, who are prepared to report, as Martha Gellhorn put it, "from the ground up, not from the top". The best traditions of journalism never change; the public has every right to demand their return.

John Pilger's 'Tell Me No Lies: Investigative journalism and its triumphs', is published on Thursday by Jonathan Cape (Random House)