When the history of modern Britain comes to be written, one of the most catastrophic failures of successive governments will be seen to have been their grotesque mishandling of our national energy policy.

In 1956, when the Queen opened the world's first commercial nuclear power station, Britain was ahead of everyone in the peaceful uses of nuclear energy. By the 1970s, when we were generating nearly a quarter of our electricity from nuclear, other countries had caught up. France, notably, launched a massive nuclear programme in the wake of the 1974 oil crisis and built the 58 nuclear plants that today provide 80 per cent of her power.

In the 1980s, Mrs Thatcher was initially keen on nuclear power, as a means to free Britain from thrall to Scargill's mineworkers. But following the leaks from Three Mile Island in 1979 and Chernobyl in 1986, nuclear energy in Britain fell into eclipse. After Sizewell B, plans for any more reactors were abandoned. Thanks to the bonanza of the North Sea, the focus of Britain's energy policy switched away from coal, oil and nuclear to gas. Britain's nuclear industry was to be allowed to die on its feet.

For nearly 20 years the image of nuclear power was dominated by the propaganda of the Green movement, vilifying it as dangerous and expensive, creating a fearful legacy of toxic waste for generations to come. Meanwhile, as Britain's nuclear engineers retired, elsewhere in the world research and development continued, holding out the prospect not only of reactors that were much cheaper and safer but also of means to dispose safely of waste.

Then, around 2000, came two further twists to the tale. First it became clear to all the experts that, as North Sea gas ran out and the bulk of our most productive coal and nuclear power plants would reach the end of their lives after 2010, Britain would face a grave energy crisis. But also alarm over global warming had by now hit the top of the agenda. Politicians in London and Brussels had become hypnotised by Green fantasies about "carbon-free renewables" and shut their eyes to the real crisis that was now fast approaching.

The nadir of this unreality was the 2003 Energy White Paper, which blethered on about wind turbines but made no attempt to address the gravity of Britain' s impending energy gap. Most glaring of all was the lack of any reference to nuclear power, still then producing 50 times more electricity than Britain's wind turbines, at less than half the unit cost - and without emitting CO2. Ministers were so firmly under the spell of Green mythology that they were determined to avoid the nuclear hot potato at all costs, even though they offered no idea how to replace the 20 per cent of generating capacity due to be lost when all but one of our nuclear plants closed in the years after 2010.

Only now, five wasted years later, has our Government belatedly begun to face up to grim reality, by announcing that it will allow the building of an unknown number of new nuclear power stations. It may already be too late to avoid massive power cuts, as some of our most productive coal-fired stations are forced to shut down by an EU emissions directive by 2014, and we must rely even more heavily on gas imports in a politically darkling world.

Because we now have so few nuclear engineers, we shall have to wait in a queue for our new plants to be built by French and other foreign companies (as late as October 2006 we sold our last world-class nuclear construction company, Westinghouse, to Toshiba, at a knock-down price of just £2.8 billion).

But not the least price we shall have to pay for allowing our once world-beating nuclear industry to disappear is that, unlike France, Japan, the USA and other countries, we can no longer play our part in the rapid advance of nuclear technology, which now holds out the prospect of "fourth generation" reactors. These will be able not only to provide cheap electricity but also, by using off-peak electricity to produce hydrogen from water, to provide unlimited CO2-free fuel for transport.

Such is the real prize for the future, a completely "hydrogen-powered" economy. For the Greens, whose crackpot ideologies have distorted EU and UK energy policy for so long, it threatens the ultimate nightmare - by robbing them of their case for ever-greater restrictions to be imposed on the motor cars and air travel they hate.

As Britain waits, down in the second division, for these crumbs to fall from the tables of those nations who stayed in the game - trying to stop our lights going out by buying nuclear-generated electricity from across the Channel - we shall look back on those politicians who allowed us to sink into such a plight as having been guilty of one of the most damaging betrayals of our age.