Next Friday is European Car Free Day. The idea, promoted by environmentalists and local authorities, is to encourage people to leave their cars at home. I think the organisers would agree that it's building up rather nicely.
Next time green campaigners want to keep cars off the road, they should dress up as truckers or farmers. When seven people tried to blockade a refinery in Essex last year, to highlight the fact that North sea oil is being given away to the companies exploiting it, they were pounced on by police. Some of them were arrested for obstruction even though they were standing on the verge.
The truckers and farmers, by contrast, seem to have been able to smash the oil industry almost casually. The oil firms insist that their capitulation has nothing to do with the fact that they too would like to see fuel duties reduced. They can't let their tankers go, they argue, because their drivers have been intimidated. When pressed yesterday, a Shell spokesman explained that on Friday last week, someone threw a traffic cone at one of the company's trucks. Next time anti-capitalism protesters want to bring the entire economic system to a halt, they should threaten it with a piece of plastic.
But it is interesting to see how easy it has been, with or without the oil companies' collaboration, to shut the United Kingdom down. If I were a hostile foreign power hoping to bring Britain to its knees, I wouldn't bother with helicopter gunships, genetically engineered bugs or indeed any form of direct combat at all. I would merely do what Nato did in Serbia, and bomb the refineries.
After the second world war, the government set out to ensure that Britain would never again be so vulnerable to an economic blockade. Alarmed by the narrowness of our escape from starvation, it set out to revolutionise British agriculture, to reduce our dependence on other nations.
Fifty years of farm subsidies have achieved precisely the opposite: far from increasing the area of Britain's farmland producing food for human beings rather than animals, they have decreased it, to just 8%. Far from reducing our imports, they have massively increased them, as we cannot now farm without vast quantities of fossil fuel, fertilisers and pesticides. As the writer Marion Shoard has pointed out, if Britain had really wanted to ensure its food security, it would have invested in horses.
Other economic sectors have been exposed to disruption by similarly clear-sighted policies. As one of my correspondents, Thomas Powell, has argued, rail had to be replaced as the principal means of transport in Britain because it was too durable. Neither the tracks nor the rolling stock wore out rapidly, with the result that turnover, and therefore profitability, were limited. The railways had to be destroyed and replaced with a system that needed continual renewal. Unsustainability is not a by- product of our road-based transport system, but its primary objective.
While railways, like roads, are vulnerable to bombing, they require far less fossil fuel to run. Indeed, with electrification, in theory they could - like most of our key services - be powered entirely by renewable energy. But today, like every other economic sector in Britain, they can be rendered inoperable simply by means of a minor disruption in the supply of a commodity largely controlled by foreign powers.
Neither government nor industry appears to be worried by the fact that our profligate energy use means our supplies of natural gas are running out. When the North sea's stocks disappear, they will be replaced by gas transported to Britain via the new "Interconnector" and pumped back into the depleted submarine reservoirs. It looks neat, until you realise that Britain's access to its primary means of power generation will depend on a pipeline running all the way from the Caspian sea - surely the most strategically exposed energy-supply scheme ever conceived. Britain, in other words, is vulnerable because it is unsustainable.
These concerns might look comfortably remote. Britain is not currently threatened by any foreign power. As members of Nato, far removed from the nations in which we have waged war, we would seem to have little cause to worry about invasion.
But if the government really believes that Britain is invulnerable, why is it spending £23bn on something called "defence" this year? Why has it been engaged in urgent discussions about whether or not our armed forces are capable of responding? I find it hard to understand how a government that claims to be so concerned about defence seems unable to grasp that it doesn't matter how much we spend on our armed forces, if the economic life of the nation can be terminated by taking out Britain's 15 oil refineries.
In fact, it might not even take hostile action to destroy us. While oil companies have sought to talk up their share prices by insisting that they have endless supplies on tap, evidence is beginning to emerge that world oil production will peak then start to slide within 20 years. If we don't do something about it pretty fast, Britain will grind to a halt whether or not our refineries are attacked.
So, quite aside from the environmental consequences of our profligate fossil fuel use, switching to dispersed self-generating power sources is surely an urgent strategic priority. The defence of the realm, in other words, depends upon investing in renewable energy.
But this government, which knows everything about tactics and nothing about strategy, has so far done as little as possible to encourage such investment. While Denmark is aiming to produce 50% of its power from wind by 2050 and Swedish researchers have developed new cells that will bring the price of solar energy down to the price of oil within 10 years, Britain, the windiest nation in Europe, has shown that it regards the issue with contempt.
First the government appointed Lord Marshall - who, as chairman of British Airways, lobbied hard against proposals to tax aviation fuel - as head of its energy tax review team. Then, last month, Tony Blair persuaded the G8 summit to elect as head of its global task force on renewable energy the chairman of Shell, a company doing its utmost to increase sales of fossil fuels. Why should we bother defending ourselves from hostile powers, when the enemy is already inside the gates?
© Guardian Newspapers Limited 2000