Leading article: The time to assign blame will come later

Day by day, we are learning just how appalling and unstoppable the consequences can be when an oil pipe that is only 21 inches wide snaps open at the bottom of the sea. When the leak was first discovered at the Deepwater Horizon rig in the Gulf of Mexico on 22 April, most observers balanced worries about an incipient environmental disaster against a comforting assumption that within a few days BP would have patched it up. After that, the focus of attention could turn to cleaning up, allotting responsibility and making sure such an event was not repeated.

Yet it's becoming apparent that the disaster is more open-ended than anyone imagined. It's far from clear that a turning point is even in prospect, though the company is talking up the chances of success of its latest plan, which involves inserting a thin tube into the ruptured pipe to siphon the oil to the surface. BP's senior executives must be praying it works out, because almost a month in, each attempt to cap the underwater volcano of oil has come to nought, mainly because of the difficulty of working at such depths.

The embattled oil giant, locked into an acrimonious row with the US government that is only likely to worsen, has thrown the book at this problem. BP's first plan was to place an underwater dome over the leak. Then there was talk of activating the failed shut-off valves which should have sprung into action as soon the pipe blew a hole. Meanwhile they have ringed the spill with a boom and deployed boats to scoop up oil from the surface.

But booms and boats are only palliative measures while the pipe continues to belch away on the seabed. What is alarming is how little progress has been made on that front. If the latest plan, to siphon the oil to the surface, doesn't work, the company will have to drill a new well to drain off the oil at source. This would take months to construct, by which time the spillage will have overtaken the Exxon Valdez spill of 1989 to become the worst oil-related disaster in history. For all we know, it could be the worst environmental catastrophe already. US scientists now believe the estimated leakage of 5,000 barrels a day to be a gross underestimate.

Against that almost apocalyptic backdrop, it's not surprising that tempers are fraying in Washington, where deep concern is giving way to panic. Barack Obama's extreme nervousness is understandable. At the moment, reports of an environmental disaster are almost academic to many Americans, because they don't actually see the oil; it's just out there, in the Gulf of Mexico. The President knows he can expect an explosion of fury once the oil washes ashore on the coast of the southern United States, blighting landscapes and destroying the livelihoods of fishermen and people working in the tourist industry. BP knows what lies ahead and knows it is in danger of losing the race against time to cap the leak – hence the defensive tone adopted by its chief executive, Tony Hayward, at the weekend. Each side is putting down markers in the dispute, struggling to set the agenda and the parameters in order to avoid coming off worst in a mounting blame game.

The US administration's desperation to deflect all blame for the spill on to the company is understandable. It is also a little hypocritical. The US government could have insisted on more rigorous security standards for offshore drilling. Too late now to say it won't allow such rigs in future. Finger-pointing, meanwhile, isn't going to help get anything done. Washington would be wise if it bit back its fury, for now, and just got on with helping BP cope with the problem. For its part, BP should stop sounding defensive when answering US demands for more clarification on the question of responsibility for the clean-up. There will be time for recrimination and name-calling over what went wrong at Deepwater Horizon. For now, both sides need to work together on plugging this leak.