Since the attacks on the United States in September 2001, there have been more than a thousand references in British national newspapers, working out at almost one every single day, to the phrase "dirty bomb". There have been articles about how such a device can use ordinary explosives to spread lethal radiation; about how London would be evacuated in the event of such a detonation; about the Home Secretary David Blunkett's statement on terrorism in November 2002 that specifically raised the possibility of a dirty bomb being planted in Britain; and about the arrests of several groups of people, the latest only last month, for allegedly plotting exactly that.
Starting next Wednesday, BBC2 is to broadcast a three-part documentary series that will add further to what could be called the dirty bomb genre. But, as its title suggests, The Power of Nightmares: The Rise of the Politics of Fear takes a different view of the weapon's potential.
"I don't think it would kill anybody," says Dr Theodore Rockwell, an authority on radiation, in an interview for the series. "You'll have trouble finding a serious report that would claim otherwise." The American department of energy, Rockwell continues, has simulated a dirty bomb explosion, "and they calculated that the most exposed individual would get a fairly high dose [of radiation], not life-threatening." And even this minor threat is open to question. The test assumed that no one fled the explosion for one year.
During the three years in which the "war on terror" has been waged, high-profile challenges to its assumptions have been rare. The sheer number of incidents and warnings connected or attributed to the war has left little room, it seems, for heretical thoughts. In this context, the central theme of The Power of Nightmares is riskily counter-intuitive and provocative. Much of the currently perceived threat from international terrorism, the series argues, "is a fantasy that has been exaggerated and distorted by politicians. It is a dark illusion that has spread unquestioned through governments around the world, the security services, and the international media." The series' explanation for this is even bolder: "In an age when all the grand ideas have lost credibility, fear of a phantom enemy is all the politicians have left to maintain their power."
Adam Curtis, who wrote and produced the series, acknowledges the difficulty of saying such things now. "If a bomb goes off, the fear I have is that everyone will say, 'You're completely wrong,' even if the incident doesn't touch my argument. This shows the way we have all become trapped, the way even I have become trapped by a fear that is completely irrational."
So controversial is the tone of his series, that trailers for it were not broadcast last weekend because of the killing of Kenneth Bigley. At the BBC, Curtis freely admits, there are "anxieties". But there is also enthusiasm for the programmes, in part thanks to his reputation. Over the past dozen years, via similarly ambitious documentary series such as Pandora's Box, The Mayfair Set and The Century of the Self, Curtis has established himself as perhaps the most acclaimed maker of serious television programmes in Britain. His trademarks are long research, the revelatory use of archive footage, telling interviews, and smooth, insistent voiceovers concerned with the unnoticed deeper currents of recent history, narrated by Curtis himself in tones that combine traditional BBC authority with something more modern and sceptical: "I want to try to make people look at things they think they know about in a new way."
The Power of Nightmares seeks to overturn much of what is widely believed about Osama bin Laden and al-Qaida. The latter, it argues, is not an organised international network. It does not have members or a leader. It does not have "sleeper cells". It does not have an overall strategy. In fact, it barely exists at all, except as an idea about cleansing a corrupt world through religious violence.
Curtis' evidence for these assertions is not easily dismissed. He tells the story of Islamism, or the desire to establish Islam as an unbreakable political framework, as half a century of mostly failed, short-lived revolutions and spectacular but politically ineffective terrorism. Curtis points out that al-Qaida did not even have a name until early 2001, when the American government decided to prosecute Bin Laden in his absence and had to use anti-Mafia laws that required the existence of a named criminal organisation.
Curtis also cites the Home Office's own statistics for arrests and convictions of suspected terrorists since September 11 2001. Of the 664 people detained up to the end of last month, only 17 have been found guilty. Of these, the majority were Irish Republicans, Sikh militants or members of other groups with no connection to Islamist terrorism. Nobody has been convicted who is a proven member of al-Qaida.
In fact, Curtis is not alone in wondering about all this. Quietly but increasingly, other observers of the war on terror have been having similar doubts. "The grand concept of the war has not succeeded," says Jonathan Eyal, director of the British military thinktank the Royal United Services Institute. "In purely military terms, it has been an inconclusive war ... a rather haphazard operation. Al-Qaida managed the most spectacular attack, but clearly it is also being sustained by the way that we rather cavalierly stick the name al-Qaida on Iraq, Indonesia, the Philippines. There is a long tradition that if you divert all your resources to a threat, then you exaggerate it."