Greenpeace is different. Having humiliated Shell in June by stopping the deep-sea dumping of the Brent Spar, the environmental group made an embarrassing discovery. It found that its claims about the amount of oil on board the installation were wrong. Yesterday Greenpeace came clean and apologised to Shell.
The error was a stupid mistake. In seriously overestimating the toxic threat, the organisation was guilty of employing juvenile science: it put the dipstick in the wrong place. Greenpeace (global income $131m last year) cannot expect to be taken seriously in future unless it is more careful. Its backing comes from people who have grown tired of cynical manipulation by government and business. They would soon give up supporting a group plagued by the same failings.
In this light, Greenpeace's apology was perhaps inevitable. The mistake was bound to be spotted eventually, since Shell has commissioned independent examination of the Brent Spar.
Nevertheless Greenpeace's decision to confess, like its campaigning throughout this controversy, is remarkable. Its significance extends beyond the environmental debate. Yet again, Greenpeace has demonstrated a very modern sophistication. It has correctly recognised that fallibility is not fatal providing the mistakes are not too serious and are combined with a measure of humility. Dishonesty, on the other hand, could destroy its reputation at a stroke. An organisation that relies on the global media depends on remaining credible. If it was caught covering up a deliberate lie, no one would ever believe its claims again. This explains why Lord Melchett, the Greenpeace UK director, was at pains yesterday to stress: "Greenpeace always tells the truth."
It was this highly ethical stance that wrong-footed Shell, one of the largest multinational companies. To the casual observer the first stages of the Greenpeace campaign seemed a waste of time, attempting to stop a decision that had long been considered and seemed irreversible.
Greenpeace was effective because it threatened to undermine Shell's reputation for honesty. It convinced people, particularly in Germany, that Shell had misled them. Consumers in Europe took the view - rightly or wrongly - that Shell, when it developed oilfields in the North Sea, had undertaken to clear up the resultant mess. Sinking plant in the ocean sounded like a breach of that undertaking. It also looked like a terrible precedent to those keen to wean Western society from its throwaway, wasteful habits.
Once Greenpeace won the ethical debate, consumers, the new arbiters of business morality, did the rest. The gathering boycott of Shell products made inevitable the abandonment of plans to dump the Brent Spar.
Critics of Greenpeace have, of course, seized on yesterday's admission in an attempt to discredit the organisation and suggest that those who work for it are prepared to play fast and loose with the truth. They are missing the point. The smart people in business and government should realise that the Greenpeace confession shows just what a serious challenge environmentalism poses. In the coming battle, honesty and integrity will be at the root of power.