Cast your mind back to the summer of 2005, to the days following the London Tube and bus bombings, and remember the shock that was felt at the discovery that the killers were British and the plot was home-grown.

It took four days for that to become clear and in that interval I believe most of us had assumed, on the basis of the story of 9/11, that this was the work of men who had come from far away to impose the violence and hatred of their world upon London. But no, they came from Leeds and Aylesbury.

Why was it a shock? Because the government, the police and the security services, as they have since admitted, had not grasped the enormity of what was happening to some disaffected British Muslims. And nor had our news media. Both government and media were like the CIA after the September 11 attacks: desperately short of human intelligence about what was suddenly the biggest challenge they faced.

The journalist Shiv Malik knew more than most about what had been going on. He had written for this magazine and others about hardline Islamism in this country, about connections with Pakistan, about the mood in places where the British National Party was active. Naturally, after the July 2005 bombs he was one of the people we at the New Statesman turned to for help - for human intelligence, if you like - and he produced a series of revealing, first-hand accounts of the bombers' world (you can still read them at www.newstatesman.com).

Since then he has continued to do this work in print and for broadcasters, most recently by writing a book about a former Islamist, Hassan Butt, though it has not yet been published.

Malik does what reporters are supposed to do: he finds his way to the heart of the story and talks to people who matter, asking important questions. It takes courage. His colour helps him gain access, no doubt, though most Muslims know instantly from his name that, by birth at least, he is not one of them. His background is Hindu and in fact he is an atheist.

Thanks to his efforts and the efforts of others like him, we the reading public now understand far more than we did in 2005 about the context and logic of the domestic terror threat. The government, the police and the security services also owe such people a debt: Jonathan Evans, the head of MI5, has described Malik's work as "essential reading".

Unfortunately, Greater Manchester Police want to render this sort of journalism all but impossible. Because they do not believe that Hassan Butt has genuinely put his extremist past behind him, they are demanding to see the research materials Malik has assembled for his book, including those acquired on the promise of confidentiality.

And, if they get their way (three high court judges will rule on the case in mid-June), they are ready to insist that the BBC, the Sunday Times, Prospect magazine and CBS also hand over their confidential papers about Butt.

The message of this will be clear: anybody who has real information about the terrorism milieu will know that talking to a reporter is no different from talking directly to the police, with all that that implies.

Reporters, and thus newspapers and broadcasters, will be unable to gather first-hand information about one of the most important stories of our time. Because people who know things won't talk to them, reporters will be reduced to talking to people who don't really know things, and we will all plunge back into the ignorance from which Malik and company have been trying to rescue us.

Actually, we will continue to have one source of information: the government and its instruments in the police and the security services. Everything we are told about the terror threat will come from them. And they, of course, will tell us no more and no less than we must know if we are to be persuaded to support them in whatever assault on civil liberties they want to perpetrate next.

Five years after our government swept us into a disastrous war on a wave of misjudgements, half-truths and downright lies, are we really ready for that? Would it not be better if there were some people, some journalists, offering us an informed alternative perspective on what is going on in this dangerous world?

Drawing the Euroline

"Britain is too proud and too full of genuine talent to submit to this annual humiliation" (Sun). "It is no longer a contest" (Mirror). "The competition has been reduced to an east European stitch-up" (Express). Not only did this year's Eurovision Song Contest reveal that there is somewhere that Sir Terry Wogan might draw the line, but it produced a chorus of outrage in the press. And rightly so, for what could be more outrageous and unBritish than a television talent contest that was not entirely fair and above board?

Brian Cathcart is professor of journalism at Kingston University