Could it happen here? The environmental disaster that followed the blow-out of the Deepwater Horizon rig in the Gulf of Mexico has shown that deep-water drilling is indeed a hazardous activity. Perhaps for too long we have taken for granted the extraordinary achievement that is the North Sea project. Forty years ago, when a startled nation first became aware that the UK might be on the verge of an oil bonanza, it was seen as one of the great engineering wonders of the world; never before had oil been extracted from such inhospitable surroundings.

The Piper Alpha disaster in 1988 brought the dangers into sharper relief. They are in sharp relief again now. There is a strong case for reassessing the costs – human, environmental, economic – and the benefits of deep-water drilling. While that is done, the precautionary principle ought to apply, and an immediate halt called to deep-water drilling off the Shetlands.

President Barack Obama has declared a moratorium on such drilling of the US coastline; the Norwegian government has followed suit in its sector of the North Sea. But our own Government's new energy minister, Charles Hendry, has only promised renewed vigilance. That is not good enough. As the world's demand for fossil fuels shows little sign of diminishing – largely driven now by the still rapidly growing economies of emerging Asia – the oil companies will continue to push the boundaries of exploration, and take more risks. In the Falklands, the Albertan oil sands and Angola, the push to squeeze out every last drop of oil goes on. But the balance of costs and benefits has been tipped by the Deepwater Horizon tragedy. "Peak oil", the point when the supply of global oil start to decline, could arrive sooner than the usual estimate of 2015.

This is the real lesson of the present crisis. Whether Tony Hayward, the chief executive of BP, survives, or whether his company is broken up is a secondary question. Another BP boss will carry on going deeper for oil; BP's assets will be taken over by another oil giant doing much the same thing in much the same way. The debate over whether President Obama has been competent in handling the present crisis is also of secondary importance. The issue here is not crisis response, but the very safety and sustainability of deep-sea drilling.

Like the banks, we see now how a big business, left for too long to its own devices, can take too many risks for the good of wider society. Like the big banks, big oil needs to be restrained.