The tragic irony of the 21st century is that just as faith in technology collapsed on the world's stock markets in 2000, it came to power in the White House and Pentagon. For the Project for a New American Century's ambition of "full-spectrum dominance" - in which its country could "fight and win multiple, simultaneous major-theatre wars" - was a monster borne up by the high tide of techno euphoria of the 1990s.

Ex-hippies talked of a wired age of Aquarius. The fall of the Berlin wall and the rise of the internet, we were told, had ushered in Adam Smith's dream of overflowing abundance, expanding liberty and perpetual peace. Fukuyama speculated that history was over, leaving us just to hoard and spend. Technology meant a new paradigm of constant growth without inflation or recession.

But darker dreams surfaced in America's military universities. The theorists of the "revolution in military affairs" predicted that technology would lead to easy and perpetual US dominance of the world. Lieutenant Colonel Ralph Peters advised on "future warfare" at the Army War College - prophesying in 1997 a coming "age of constant conflict". Thomas Barnett at the Naval War College assisted Vice-Admiral Cebrowski in developing "network-centric warfare". General John Jumper of the air force predicted a planet easily mastered from air and space. American forces would win everywhere because they enjoyed what was unashamedly called the "God's-eye" view of satellites and GPS: the "global information grid". This hegemony would be welcomed as the cutting edge of human progress. Or at worst, the military geeks candidly explained, US power would simply terrify others into submitting to the stars and stripes.

Shock and Awe: Achieving Rapid Dominance - a key strategic document published in 1996 - aimed to understand how to destroy the "will to resist before, during and after battle". For Harlan Ullman of the National Defence University, its main author, the perfect example was the atom bomb at Hiroshima. But with or without such a weapon, one could create an illusion of unending strength and ruthlessness. Or one could deprive an enemy of the ability to communicate, observe and interact - a macro version of the sensory deprivation used on individuals - so as to create a "feeling of impotence". And one must always inflict brutal reprisals against those who resist. An alternative was the "decay and default" model, whereby a nation's will to resist collapsed through the "imposition of social breakdown".

All of this came to be applied in Iraq in 2003, and not merely in the March bombardment called "shock and awe". It has been usual to explain the chaos and looting in Baghdad, the destruction of infrastructure, ministries, museums and the national library and archives, as caused by a failure of Rumsfeld's planning. But the evidence is this was at least in part a mask for the destruction of the collective memory and modern state of a key Arab nation, and the manufacture of disorder to create a hunger for the occupier's supervision. As the Süddeutsche Zeitung reported in May 2003, US troops broke the locks of museums, ministries and universities and told looters: "Go in Ali Baba, it's all yours!"

For the American imperial strategists invested deeply in the belief that through spreading terror they could take power. Neoconservatives such as Paul Wolfowitz, Richard Perle and the recently indicted Lewis "Scooter" Libby, learned from Leo Strauss that a strong and wise minority of humans had to rule over the weak majority through deception and fear, rather than persuasion or compromise. They read Le Bon and Freud on the relationship of crowds to authority. But most of all they loved Hobbes's Leviathan. While Hobbes saw authority as free men's chosen solution to the imperfections of anarchy, his 21st century heirs seek to create the fear that led to submission. And technology would make it possible and beautiful.

On the logo of the Pentagon's Information Awareness Office, the motto is Scientia est potentia - knowledge is power . The IAO promised "total information awareness", an all-seeing eye spilling out a death-ray gaze over Eurasia. Congressional pressure led the IAO to close, but technospeak, half-digested political theory and megalomania still riddle US thinking. Barnett, in The Pentagon's New Map and Blueprint for Action, calls for a "systems administrator" force to be dispatched with the military, to "process" conquered countries. The G8 and a few others are the "Kantian core", writes Barnett, warming over the former Blair adviser Robert Cooper's poisonous guff from 2002; their job is to export their economy and politics by force to the unlucky "Hobbesian gap". Imperialism is imagined as an industrial technique to remake societies and cultures, with technology giving sanction to those who intervene.

The Afghanistan war of 2001 taught the wrong lessons. The US assumed this was the model of how a small, special forces-dominated campaign, using local proxies and calling in gunships or airstrikes, would sweep away opposition. But all Afghanistan showed was how an outside power could intervene in a finely balanced civil war. The one-eyed Mullah Omar's great escape on his motorbike was a warning that the God's-eye view can miss the human detail.

The problem for the US today is that Leviathan has shot his wad. Iraq revealed the hubris of the imperial geostrategy. One small nation can tie down a superpower. Air and space supremacy do not give command on the ground. People can't be terrorised into identification with America. The US has proved able to destroy massively - but not create, or even control. Afghanistan and Iraq lie in ruins, yet the occupiers cower behind concrete mountains.

The spin machine is on full tilt to represent Iraq as a success. Peters, in New Glory: Expanding America's Supremacy, asserts: "Our country is a force for good without precedent"; and Barnett, in Blueprint, says: "The US military is a force for global good that ... has no equal." Both offer ambitious plans for how the US is going to remake the third world in its image. There is a violent hysteria to the boasts. The narcissism of a decade earlier has given way to an extrovert rage at those who have resisted America's will since 2001. Both urge utter ruthlessness in crushing resistance. In November 2004, Peters told Fox News that in Falluja "the best outcome, frankly, is if they're all killed".

But he directs his real fury at France and Germany: "A haggard Circe, Europe dulled our senses and fooled us into believing in her attractions. But the dugs are dry in Germany and France. They deluded us into prolonging the affair long after our attentions should have turned to ... India, South Africa, Brazil."

While a good Kleinian therapist may be able to help Peters work through his weaning trauma, only America can cure its post 9/11 mixture of paranoia and megalomania. But Britain - and other allied states - can help. The US needs to discover, like a child that does not know its limits, that there is a world outside its body and desires, beyond even the reach of its toys, that suffers too.

· Dr Richard Drayton, a senior lecturer in history at Cambridge University, is the author of Nature's Government, a study of science, technology and imperialism

RHDrayton@yahoo.co.uk