IT IS no easy task to gain some understanding of human affairs. In some respects, it is harder than the natural sciences. Mother Nature doesn’t readily provide the answers, but at least she doesn’t go out of her way to set up barriers to understanding.

In human affairs, it is necessary to detect and dismantle barriers erected by doctrinal systems, which adopt a range of devices that flow very naturally from concentration of power.

To facilitate the marketing effort, doctrinal systems commonly portray the current enemy as diabolical by its very nature. The characterisation is sometimes accurate, but the crimes are rarely the source of the call for forceful measures against some target that stands in the way of current plans.

A recent illustration is Saddam Hussein — a defenceless target characterised as an awesome threat to our survival who was responsible for Sept. 11 and about to attack us again.

In 1982, the Reagan administration dropped Saddam from the list of states supporting terrorism so that the flow of military and other aid to the murderous tyrant could begin. It continued long after Saddam’s worst atrocities and the end of the war with Iran, and included the means to develop weapons of mass destruction. The record, hardly obscure, falls under the "general tacit agreement that ‘it wouldn’t do’ to mention that particular fact," in Orwell’s phrase.

It is necessary to create misimpressions not only about the current "Great Satan" but also about one’s own unique nobility. In particular, aggression and terror must be portrayed as self-defence and dedication to inspiring visions.

Emperor Hirohito of Japan, in his surrender declaration in August 1945, told his people, "We declared war on America and Britain out of our sincere desire to ensure Japan’s self-preservation and the stabilisation of East Asia, it being far from our thought either to infringe upon the sovereignty of other nations or to embark upon territorial aggrandisement."

The history of international crimes overflows with similar sentiments, including the lowest depths. Writing in 1935, with the dark clouds of Nazism settling, Martin Heidegger declared that Germany must now forestall "the peril of world darkening" beyond the nation’s borders. With its "new spiritual energies" revived under Nazi rule, Germany is at last able "to take on its historic mission" of saving the world from "annihilation" by the "indifferent mass" elsewhere, primarily America and Russia.

Even individuals of the highest intelligence and moral integrity succumb to the pathology. At the peak of Britain’s crimes in India and China, of which he had an intimate knowledge, John Stuart Mill wrote his classic essay on humanitarian intervention, urging Britain to undertake the enterprise vigorously — even though it will be "held up to obloquy" by backward Europeans who can’t comprehend that England is "a novelty in the world," a nation that acts only "in the service of others," selflessly bearing the costs of bringing peace and justice to the world.

The image of righteous exceptionalism appears to be close to universal. For the United States, one constant theme is the dedication to bring democracy and independence to a suffering world.

The standard story in scholarship and in the media is that US foreign policy contains two conflicting tendencies. One is what is called Wilsonian idealism, which is based on noble intentions. The other is sober realism, which says that we have to realise the limitations of our good intentions. Those are the only two options.

Whatever the operative rhetoric, it takes discipline not to recognise the elements of truth in historian Arno Mayer’s observation that since 1947, America has been a major perpetrator of "state terror" and other ‘rogue actions,’ causing immense harm, "always in the name of democracy, liberty and justice."

For the US the longtime enemy has been independent nationalism, particularly when it threatens to become a "virus," to borrow Henry Kissinger’s reference to democratic socialism in Chile after Salvador Allende was elected president in 1970. The virus therefore had to be extirpated, as it was, on Tuesday, Sept. 11, 1973, a date often called "the first 9/ll" in Latin America.

On that date, after years of US subversion, Gen. Augusto Pinochet’s forces attacked the Chilean Presidential palace. Allende died, an apparent suicide, unwilling to surrender to the assault that demolished Latin America’s oldest and most vibrant democracy, and Pinochet established a brutal regime. The official death toll of the first 9/11 is 3,200; the actual toll is commonly estimated at about double that figure. In per capita terms, that would amount to 50,000-100,000 killed in the US.

Washington firmly supported Pinochet’s regime, and had no slight role in its initial triumph. Pinochet soon moved to integrate other US-backed Latin American military dictatorships in the international state terrorist network, Operation Condor, that wreaked havoc in Latin America.

This is one of all-too-many illustrations of "democracy promotion" in the hemisphere and elsewhere. Now we are led to believe that the US mission in Afghanistan and Iraq is to bring democracy there.

"Muslims do not ‘hate our freedom,’ but rather they hate our policies," concludes a report last September by the Defence Science Board, a Pentagon advisory panel, adding that "when American public diplomacy talks about bringing democracy to Islamic societies, this is seen as no more than self-serving hypocrisy." As Muslims see it, the report continues, "American occupation of Afghanistan and Iraq has not led to democracy there, but only more chaos and suffering."

In a Financial Times article in July, citing the DSB report, David Gardner observes: "For the most part, Arabs plausibly believe it was Osama bin Laden who smashed the status quo, not George W. Bush, (because) the 9/11 attacks made it impossible for the West and its Arab despot clients to continue to ignore a political set-up that incubated blind rage against them."

It should come as no surprise that the US is very much like other powerful states, past and present, pursuing strategic and economic interests of dominant sectors to the accompaniment of rhetorical flourishes about its exceptional dedication to the highest value.

Against the backdrop of the disaster unfolding in Iraq, an uncritical faith in good intentions only delays a desperately needed redress of approach and policy.

Noam Chomsky is a professor of linguistics at the Massachusetts Institute of Technology and the author, most recently, of Imperial Ambitions: Conversations on the Post-9/11 World, published by Metropolitan Books