In times of war, Mafia families are known to vacate their homes and find safe areas to protect themselves. Described in the Commons as "the first mafia boss in history who didn't know he was running a criminal enterprise", James Murdoch has kept in character and duly obliged by "going to the mattresses".

Britain is no longer safe territory for Murdoch Jnr. Sue Akers, the Iron Lady who now heads the Met's attack dogs, let it be known a few days ago that the ineffective poodles who had previously looked at News International have been replaced with Rottweilers.

Time will tell how true that is. But neither James Murdoch, nor the angry shareholders of News Corp in New York, nor perhaps his father, have the luxury of time to wait and see.

Phone hacking and police corruption was the systematic criminal culture that kept the Murdoch brand top dog in the UK tabloid wars. But the relentless revelations around phone hacking and illegal payments to police and public officials have exposed and torn down that culture, labelled it poisonous – leaving James, in his role as News International's protector and defender of his father's creations, a failure. That more is to come is not a prediction; it is a certainty.

When the News of the World's successor, a Sunday version of The Sun, was launched last week, it was Murdoch senior, the capo di tutti capi, the boss of all News Corp's bosses, who arrived in London from New York with his son Lachlan to do the job himself. James was nowhere to be seen.

The official News Corp line is that James will now focus on expanding the company's international television businesses in New York. The reality? He has been removed from the front line of the hacking scandal.

That points to a number of consequences. One, News Corp's focus will now be the lucrative markets that no longer include Britain. Two, that James Murdoch remains damaged goods, toxic enough to cause News Corp shares to surge by 2 per cent yesterday after the news, based on a mini-celebration that he's at last really leaving.

The kindest analysis, which should be dismissed as holding little long-term value, is that Rupert is returning to rehabilitate and re-energise, giving Wapping a coat of year-zero paint.

That won't be enough. Deputy Assistant Commissioner Akers and operations Weeting, Tuleta and Elveden all remain an in-tray of constant trouble for the company.

James's unconvincing performances in front of Westminster's serial inquisitions on phone hacking, when he offered poor explanations of what he did not know, did not read, and did not bother asking, left him looking like an executive out of his depth.

Those appearances, along with contradictory evidence offered by former lieutenants gone rogue, and who refused to take the bullet for their boss, simply stored up, rather than cleaned up, the hacking mess.

Although New York is off limits for Scotland Yard, that does not mean Murdoch Jnr is beyond their legal reach. Nor will his retreat from Fortress Wapping calm the attorneys in the US Department of Justice, all anxious to show their worth in a presidential election year.

With James out of London, and no Murdoch left in Wapping, a more potent commercial question has just been asked. If Murdoch Jnr's departure is a devaluation of the family's UK silver, does News Corp really need, or even want, News International any more?