John Rentoul: Reid now finds himself locked in battle with Cameron. Victory is not assured

The PM's motive in backing it was not to be horrible to Muslims

It is reasonable to believe both that the police are incompetent and that the raid on a house in Forest Gate was completely justified. Both of these would have to be beliefs rather than assertions, though, because few people yet have a clear idea of precisely what happened in that house in east London where a young man was shot in the shoulder nine days ago. We do not know for sure that the raid was badly handled, although recent history and the fact that 250 officers were deployed do not inspire confidence. Nor do we know how credible the intelligence was on which the operation was based, although the release of the two brothers without charge suggests it was dud.

Non-white Londoners are entitled, therefore, to feel concerned about the way the police conducted the operation. The idea of being shot by mistake by an officer breaking into one's house at 4am can hardly be waved aside as a regrettable piece of bad luck. Yet many of the angry protests of political Muslims and their hard-left secular fellow travellers go much, much farther. They take it as given that the tip-off about a chemical bomb on the premises was wrong, and that this should have been obvious beforehand.

Many of the critics of the operation have suggested, in effect, that Eliza Manningham-Buller, the head of MI5, should have said: 'Well, you may think your tip-off is credible, Agent X, but I say we ignore it and concentrate on planning the office summer party. We don't want to upset the locals, do we?" Various smart alecs have written letters to the newspapers saying that, because the intelligence services got it wrong about Saddam Hussein's chemical and biological weapons, they were obviously wrong on this occasion.

Worse than that, the many people who think that the spies made up the intelligence about Saddam are delighted to believe that MI5 has fabricated the intelligence this time. The reasons why the security services are thought to make things up dissolve into muttered confusion if such nonsense is challenged. It is "all about oil", or the war being used to stifle dissent and scare people into voting, er, Labour. More dangerous - and this has infected the conspiracy theorising about Forest Gate - is the idea that the motive behind the invasion of Iraq and indeed the whole "war on terror" is to oppress Muslims. "Fear is what keeps people on-side in Blair's war on terror," wrote Faisal Bodi in The Guardian last week, "and few things provoke more alarm than special forces in chemical suits descending on a city street."

Well, one thing that ought to provoke more alarm would be the idea that, if the security services obtain intelligence that someone is making a chemical bomb, they would do nothing about it. You do not have to be a founder member of the Blair Appreciation Society to doubt that the Prime Minister's motive in backing the police raid, or in joining the invasion of Iraq, was to be horrible to Muslims.

So it is important to try to separate the real issues from the "Tony Blair Crusader" placards carried by the small crowd of protesters in Forest Gate on Friday, who may assemble for a larger demo today. The two real issues are the quality of intelligence and the competence of the police. Crispin Black, the former member of the Cabinet Office assessment staff and author of a book about the London bombings, has commented in these pages about the slowness of the response of the British security services to 9/11. The services did not use the money pumped in to expand operations as quickly as they should have done. It may be that MI5, which would have made the decision to act on the Forest Gate intelligence, was over-compensating for its humiliation last year, and its failure to act on its suspicions about the leader of the 7/7 bombers. But is that not how it should be? Would we not prefer our intelligence services to be nervous on our behalf about any hint of terrorist activity?

The larger question, therefore, is one of police competence. It seems extraordinary - the decision to intervene having been taken by the spies - that the police should have used so many people and so much kit to raid a private house. "It was as if they were going into a secret lab at Porton Down," said one former spy. The whole point of going in at 4am was presumably to take the occupants by surprise, before they could activate any device.

It plays out against the unfortunate background hum of the impending report on the killing of Jean Charles de Menezes. No one imagines that managing such operations can be easy, but an effective police chief would have to demonstrate that his force can learn quickly and flexibly from mistakes. From what we already know about Sir Ian Blair's way of working, it seems that the Metropolitan Police Commissioner is more of a politician - not a very good one - than a manager. It is hard to see how he can survive the Menezes report, but a new commissioner for London does not necessarily solve the wider problem.

That is up to the real politicians. It is primarily a struggle between David Cameron and John Reid, the new Home Secretary. So far, Labour has shied away from fundamental reform of the police. It is highly symbolic that so much of the Government's energy over the past year has been absorbed by the attempt to reorganise police forces into bigger regional units. It is an attempt to drive change from the top rather than to do what matters: change working practices, improve management skills and allow innovation to spread from the bottom up.

It was one of Cameron's more astute ideas to describe the police as "the last great unreformed public service", and to say: "We shouldn't treat them with kid gloves just because officers do a brave job." Blair rebuked him, saying: "It is all very well to talk, as he does, about incompetent or lazy police officers, but I do not think that that is the problem with the police." That is old New Labour thinking: there may now be limits to a politics based on "101 per cent support" for the police. Most people - and many police officers - recognise the need to drag a form-filling bureaucracy into the electronic age.

One of the first things John Reid did when he took over the Home Office last month (after being criticised for going on holiday) was to put on a stab-proof vest to join police officers in a raid on suspected illegal immigrants. It was a good thing he didn't join the Forest Gate raid. But now he needs to create a police force that can mount such operations with agility, confidence and intelligence - in both senses of the word. If he fails, Cameron is ready to pounce.