Whoever leaked the photographs of torture scenes in the Abu Ghraib prison was doing us all a great service. The Mirror fakes are unfortunate, but the rest is real and pants are on fire all over Washington. Which is as it should be.

On top of their imperialist adventure in Iraq, Bush and Blair have brought about a sea-change in people's perceptions of power. It's now perhaps easier than ever before to believe that once politicians get real power, they serve their own interests and those of other power-holders - political and corporate. It's easier to believe that representation and democracy have become little more than convenient devices for holding on to power - more useful than tyranny, and much more refined. Or that psychologically there is something not quite right about politicians, that even democratic leaders are somewhere on the same scale that includes Charlemagne, Ivan the Terrible and Henry VIII. Or, indeed, that politicians are criminals who legitimise their own crimes.

If such perceptions have any truth in them - and even if they don't, in order to prevent there ever being truth in them - then disclosure becomes one of the supreme political values. One of its primary virtues is that, unlike freedom, loyalty, patriotism, it has none of the Orwellian corruptions; it is not a Newspeak word. It means, no more and no less, that it is necessary to disclose to the public what politicians try to conceal or spin, and that individuals and groups who do this are to be admired and approved.

The makers and publishers of the genuine torture photos are following in the tradition of one of the greatest whistle-blowers of all time: Edmond Dene Morel, the investigative journalist who in the early twentieth century told the world about the bloody regime of King Leopold II of the Belgians in the Congo Free State - a regime of slavery and genocide that still shocks us today, even after the surfeit of horrors that have darkened the hundred years between Morel's time and ours. 2004 is the centenary of the publication of Morel's book, King Leopold's Rule in Africa. Morel should be recognised, in this year and always, as a pioneer of disclosure.

He was an insider, to begin with: a representative in Belgium of the shipping line Elder Dempster, which had a monopoly of the Congo trade. In later life he was to become a friend of Arthur Conan Doyle, creator of Sherlock Holmes; but as the historian Adam Hochschild puts it, in the course of his work at Antwerp Docks 'the young Morel made a deduction more far-reaching than anything accomplished by Holmes'. Simply from observing the loading and unloading of ships that plied between Antwerp and the Congo, noting that rubber and ivory were arriving in huge quantities and little or nothing other than weapons was going the other way, he deduced that the Congo regime must be based on oppression and forced labour.

A thorough trawl through Liverpool shipping records confirmed his intuition: the gross imbalance between the value of imports from the Congo, and that of exports to the Congo (which in any case included arms), was such that it was impossible that anyone in the Congo (except white colonialists and entrepreneurs) was being paid either for the goods or for the labour of producing them. From the time of that discovery, Morel single-mindedly and tirelessly pursued the realities of this brutal oppression, until the world knew the truth.

Unable to get adequate coverage in what we would now call the mainstream media, he started his own newspaper, the West African Mail. He obtained - from other whistle-blowers, of whom there was no shortage - and published secret documents of the colonial regime and the concession companies working for it. He published official records of women and children kidnapped and held hostage to force their husbands to work without pay as rubber-harvesters. He published casualty lists of the names of Congolese people, with the means of death detailed beside each name: 'shot', 'killed with the butt of a rifle'. (A hundred years later, Iraqi dead are still not even officially counted, far less listed by name.) Every claim made by the colonial authority, every denial of atrocities, Morel countered with facts and eye-witness accounts.

Largely owing to Morel's campaign, in June 1903 the British Parliament carried a resolution committing the Government to act together with other European powers 'in order that measures be adopted to abate the evils prevalent in [the Congo Free State]'. Roger Casement, British Consul in the Congo, was sent on a fact-finding expedition. His report was a powerful indictment of the Belgian regime, sparing no details of castrations, the severing of hands and feet, the suspension of 'renegade' workers by their hands for days in the baking sun without food or water, the burning of villages.

In the longer term, though, these were small victories. The power-holders and money-men are not that easy to crack. The fact that Morel and Casement and others have brought so much wickedness into the light of day doesn't necessarily mean that power-practitioners mend their ways. In fact, the effect on Leopold's royal Murder Incorporated was relatively slight. Up to and after his death in 1909, reform came very slowly. The death-toll reached 10 million - half the Congo's population. During World War 1, thousands of Congolese were dragooned into forced labour again, this time for the timber and mining corporations. World War two brought more wretchedness: most of the uranium in the Hiroshima and Nagasaki bombs was mined in the Congo by slave, or near-slave, labour. The first democratic prime minister of the Congo, Patrice Lumumba, was murdered with the connivance and support of the CIA, and a contemptible kleptocrat, Mobutu Sese Seko, was bunked up to power in his place. Most recently we have had a plethora of gangs, militias and liberation armies killing one another over tin, diamonds, and the very coltan in our mobile phones.

Yes, disclosure is a hard road and an uphill struggle. But it often seems to me the best of the political virtues - significantly, one not usually practised by politicians - and one of the few worth breaking sweat over.

If public distrust and antipathy towards politicians is deeper now than ever before, at the same time acts of disclosure are more effective than ever. At the level of communications we have now, far more people can be in the know than was possible in Morel's time. In our world, too, the Congo or Iraq seem far less remote or exotic places. The torture pictures from Iraq are much less strange to us than early photographs of mutilated Congolese villagers, or militiamen holding up severed hands. And if public awareness and protest are more easily heightened, the effect of disclosure on power-groups is also more immediate. Morel had to keep up his war of words for ten years before he could feel he was making inroads. Neither Leopold nor his British allies could easily be made to run around like headless chickens. Now, within days, ministers are busy being appalled, apologising, and even - if there's a real panic - actually making policy changes. Even those fake pictures threw ministers into confusion, and brought admissions that reports of abuses had been around for some time, but that no-one in the Government had thought of paying attention to them.

But what matters most is this. Even if disclosure doesn't always soften the hard hearts of power-holders, it does succeed in raising public consciousness. In the 'us versus them' world we find ourselves in (and sadly it's becoming more and more us the people versus them the leaders) disclosure ensures that we are better-informed and better-armed as governments more and more serve interests other than ours: mainly those of corporations and the American empire. And even if the present level of distrust turns out to be only a phase brought on by Bush-Blair chicanery, and representative democracy can still heal itself - even so, it's better to be able to see through political evasions and manipulations as often and as penetratingly as we can.

Morel and Casement and others like them should be celebrated. There should be public holidays in their honour, and TV documentaries to remind us of their achievements. Children in school should be told Morel's story - it's one that young children are well able to understand - and taught that he was a good man and that Leopold was a criminal - by no means the only criminal to have borne the title of King - or President, or Prime Minister.


For information on Congolese history and Edmond Morel, I am indebted to Adam Hochschild, King Leopold's Ghost (Macmillan 1998) and to the New Internationalist magazine.