Bruce Anderson: Steve Hilton rewarded David Cameron with one of the most despicable instances of disloyalty in political history

Last week Steve Hilton left his job at 10 Downing Street. Bruce Anderson reflects on the "highly divisive background briefing" - including claims of £25 billion in extra welfare cuts, the uselessness of the civil service and a 'chillaxed' style of premiership - that has been credited to the PM's outgoing guru, all sourced from a series of valedictory lunches.

Steve Hilton had some outstanding qualities, which is just as well for him. Otherwise, a man who can also be so impossible could not have survived in any important role. David Cameron hired him, respected him and put up with him because of his creative energy. He has now rewarded his boss and close friend with one of the most despicable instances of disloyalty in political history. At this fraught juncture, serious people in No.10 have had to divert time and energy to refuting Mr Hilton's poisonous and nonsensical briefings. As a Prime Ministerial advisor, he turned out to be a whining, egomaniacal perpetual adolescent.

It could have been so different. The oysters of government can benefit from infusions of grit. The team is better if it includes someone who is constantly trying to extend the frontiers of the possible. That should have been Steve's role: the orchestrator of creative tension. But he failed. It was all tension and no creativity.

Government is difficult. It is not like driving a small motor-boat around a sheltered harbour. It is much more a case of steering a vast super-tanker through narrow waters, in darkness, when the charts no longer seem to give a clear picture of the rocks ahead. In this hazardous voyage, the civil service has a crucial role, as the custodian of risk-averseness. Civil servants have the job of pointing out difficulties; frequently, of telling ministers what they do not want to hear. Dealing with really good civil servants in a cautious mood can be like stuffing newspaper through wire mesh, but there is a consolation. Once a policy has been argued over and hammered out and drafted by a conclave of intelligent and determined minsters plus their very able advisors, it should stand up to the buffets and storms of the outside world. If the Minister's nerve fails, there are only two conclusions. Either the policy is no good, or the Minister is no good - or, of course, both.

Policy is not to be confused with fantasy, which was Steve's endemic problem. It is simply no use suggesting a course of action that would involve the Prime Minister in breaking the law. Nor is there any point in proposing to abolish the civil service. Partly because the Labour government spent thirteen years in demoralising them, many civil servants are not functioning properly. In some areas, there has been a failure of leadership. But that cannot be rectified by witless denigration.

In government, everything needs to be thought through. The major tasks must be approached in the spirit of Montgomery planning a battle and a victory, not of Prince Rupert taking a punt on a cavalry charge. Steve would come up with a scheme. People would tell him why it would not work. Instead of trying to deal with the objections, Steve would sulk. Then articles would appear claiming that the Hilton proposals would go ahead. At the beginning, Steve was a good friend of George Osborne's as well as David Cameron's. By the end, Mr Osborne had become terminally exasperated.

Government is an exasperating business. Everything seems to cost more and take longer than expected. Colleagues turn out not to be up to it - and these days, there is the constant threat of chaos from abroad. So it is vital that the command and control centre in No.10 should be a still point of the turning world. Yet Steve would often behave like a hold-over from Gordon Brown's days, generating wholly unproductive emotion and anger.

The PM tolerated this for three reasons. First, he never saw the worst aspects of Steve's behaviour. Second, David Cameron knows himself to be an inveterate English pragmatist. At least in private, most Prime Ministers indulge in 'what if' moments, thinking wistfully what it would be like if the constraints of reality were less burdensome. Not Mr Cameron: he is a consummate realist. So the attraction of an absolute romantic, especially one from such an extraordinary background, is easy to understand. David Cameron would refer to Steve as the little Hungarian fascist; it was meant affectionately. Finally, with all faults, as they would say in the antiquarian book-trade, Steve is likeable.

But he has behaved so badly. He has let everybody down: his colleagues, his friend the Prime Minister - and himself. His reputation does not deserve to recover. If you are in his job, there should be a bond of absolute loyalty. If he disagreed with what was happening, he had any amount of access to the PM to make his own case. If he still found the situation intolerable, his duty was clear: to resign. Instead, he has created a myth: that there was a radical moment in which David Cameron could have transformed the country, if only he had listened to Steve Hilton. There was never a radical moment. There has merely been a radical two years. Health, education and welfare: British social policy has been transformed, with little input from Steve. To be fair, he did fling himself into one major initiative: the Big Society. Two years later - no-one knows what it means.

It is still not clear why exactly he has gone to California. He has let the world know that he was fed up with the government. As he is also uxorious and devoted to his small children, he hated being so separated from his family. Would he have left Downing Street if he had been less disillusioned? It is probably impossible to tell.

But he should feel at home in his new surroundings. His children are at the age when they start chucking toys out of the pram. So Steve will be able to chuckle delightedly and say: "That's what Daddy used to do, when he worked for the Prime Minister".