Even in the depths of a crisis, Rupert Murdoch's flair for the dramatic never deserts him. Yesterday's announcement that the News of the World, the newspaper at the centre of the phone-hacking scandal, is to be closed down was as sensational as any of the stories the scandal sheet has carried on its front page in its 168-year history.

On the face of it, this represents an astonishing capitulation. The News of the World has the largest circulation of any publication in the English-speaking world. It was also Mr Murdoch's first newspaper acquisition on these shores, his bridgehead onto the British media back in 1969. Some wondered yesterday whether they were hearing the first sounds of a mighty empire crumbling.

Yet there is also a cold commercial logic to this amputation of one of the oldest and most colourful parts of the Murdoch regime. This week's revelations that the phones of terrorism victims and British soldiers killed in action were hacked were lethal blows to the News of the World's brand. The paper was haemorrhaging advertising revenue, with some of the largest UK businesses deciding that they could no longer afford to be associated with such an organisation. And despite its vast circulation, the News of the World is not profitable.

No – the sound that could be heard yesterday was not of an empire crumbling, but an empire attempting to shore up its defences and protect its key personnel. The purpose of this move is to prevent the rest of the sprawling Murdoch media organisation from contamination. There was a danger that UK advertisers would withdraw their custom not only from the News of the World, but also from Mr Murdoch's other UK newspapers, The Sun, The Times and The Sunday Times. Mr Murdoch will have also realised that there was no chance of News Corporation's planned acquisition of the broadcaster BSkyB being allowed to go ahead by the Government without some dramatic demonstration of internal reform.

What we heard yesterday might also turn out to have been the sound of cynical manoeuvring. There are suggestions that The Sun, the News of the World's daily stablemate, will turn into a seven-day operation and take the place of the News of the World on the Sunday news stands. If this is the case, this will turn out to be nothing more than a giant re-branding exercise, as Ken Clarke pointed out yesterday.

Whether those suspicions are vindicated or not, no one should imagine that this move draws a line under the affair. Even if Mr Murdoch never publishes another tabloid newspaper on Sunday in Britain again, the fact remains that the management team that presided over the phone-hacking scandal, that repeatedly covered up evidence of wrongdoing, that misled parliament, remains in place. Rebekah Brooks, who was editor of the News of the World at the time the phone of the murdered teenager, Milly Dowler, was hacked, is still chief executive of News International, News Corporation's UK subsidiary. James Murdoch, who approved out-of-court payments to buy the silence of public figures whose privacy had been illegally invaded, is now a senior executive at News Corporation in New York. The life of a notorious newspaper might have been extinguished yesterday, but the stench of cover-up and criminality hangs as thick as ever in the Murdoch court.