In order to understand why Damian Green was arrested with such spectacular insensitivity, take a look at how the next Chief of the Metropolitan Police will be appointed.
The deadline for applications passed yesterday. As from today, senior officials from the Home Office will draw up a shortlist. The smaller list of candidates will then be interviewed by the Metropolitan Police Authority, which will make its recommendation.
The Mayor of London will have a say in the appointment but the Home Secretary will make the final decision. The successful candidate will then be accountable in different ways to the three bodies which played a part in his or her appointment. Yet, as Green's arrest demonstrates, at imprecisely defined times the next Chief will also be able to take decisions without political masters getting overtly involved.
The connections between the Metropolitan Police and those to whom the body is supposedly accountable are hopelessly confused and blurred. It is in the confusion that calamitous misjudgements are made. Every five minutes I hear or read that Green's arrest shows that we are heading towards a police state. Yet the arrest proves the precise opposite. The police defied one of its rulers and did not consult others who supposedly preside over them.
Gordon Brown and Jacqui Smith have said unequivocally that they did not know in advance. There are evasive answers for political leaders when they want to avoid a question. There is no need to lie. Brown and Smith did not deploy famously vacuous phrases about their reluctance to give a running commentary while the investigation continued. They said they did not know about this specific arrest in advance. Believe it or not, when they are as clear as that, they did not know.
The Mayor of London, Boris Johnson, was told in advance by the acting Metropolitan Chief, Sir Paul Stephenson. With good cause he tried to talk him out of the demented excursion. Johnson failed to persuade Stephenson. The exchange highlights again the fuzzy lines of control. Johnson was powerful enough to remove Sir Ian Blair. He had no influence over whether the police arrested and detained for nine hours a Conservative MP who had received some leaked information.
For those of us who followed closely the "cash for honours" investigation, this is familiar terrain, although it is a novelty this time to be joined by the rest of the media in a loud chorus of condemnation of the police tactics.
I seem to remember that the investigation into cash for honours was hailed as heroic by many of those attacking the latest operation. The difference is that Tony Blair and his entourage were out of fashion, while an opposition MP with leaked material is a more appealing figure for crusaders across the political spectrum. But the intimidating dawn arrest of Blair's adviser, Ruth Turner, was as over the top and ill judged as the invasion of counter-terrorism officers into Green's home.
Like the Green affair, the cash for honours investigation does not exactly point to a police state. Again it pointed in the opposite direction. In that case a ruler might have been toppled by the hyper activity of an expensive police inquiry.
In some ways Green's arrest is the more complex of the two equally depressing sagas. The cash for honours investigation should never have started, triggered as it was by the submission of a newspaper cutting from a single MP. In this latest case the police had no choice but to carry out an investigation into leaks at the Home Office once the Permanent Secretary asked them to do so. The main area of alarm relates more to the way they went about intimidating Green and taking information from his home and office. More specifically, the question narrows to this: Should politicians have the right to intervene in operational plans of the police?
Even here the current arrangements are confused. On Sunday the former Home Secretary, Ken Clarke, said he would be amazed if such an operation had not been authorised politically. But yesterday another former Home Secretary, Jack Straw, said he could not recall being consulted on precise operational matters. This is the line taken by Smith, who insists that vaguely-defined operational procedures are a matter for the police, not least when they are carrying out an investigation instigated by the Home Office. There is something in this. I can imagine an equally big media frenzy if politicians did interfere in a police investigation.
But there is a bigger problem with the current arrangements. If the police had consulted their various political bosses, they would presumably have received contradictory advice. The Mayor would have given the thumbs down. Presumably Smith would have given the go-ahead – although I suspect the Government would have thought twice. Being an instinctive journalist who can see a headline coming a mile off, Gordon Brown would have worried about the endless stories of a police state.
I am told there have been anguished discussions in No 10 about how to deal with a story that will run for a long time to come. Merely trumpeting the independence of the police is not enough – as comically inadequate as the original arrest was grotesquely over the top.
Whenever I look at a public service I ask a single question: How are those in charge held to account? If the answer begins with the words, "Well, it's a bit complicated....", I know for sure that there will be big problems with the service. Clear lines of accountability and responsibility keep practitioners on their toes in ways that can be creative and constructive. When there is confusion there will be cock-ups and misjudgements galore.
In the case of Green's arrest and cash for honours, the cock-ups related partly to a misunderstanding on the part of the police as to the way politics works. It seems they leap too quickly to an assumption of possible criminality, when the desperate amoral expediency of raising money for parties or the use of leaks to challenge a government are a part of politics.
How can matters be improved? Once the various authorities have appointed a new Met Chief they need to decide more clearly who is accountable to whom and in what circumstances. Far from being a police state, the Green saga shows that in Britain no one knows who is in control of what.