Crispin Black: If only al-Qa'ida were run by our spineless spy masters

We didn't pick up on Khan because we didn't have enough people

The committee appointed by the Prime Minister, and charged with overseeing the intelligence services, boasts on its website that it "operates within the 'ring of secrecy' and has wide access to the range of Agency activities and to highly classified information". But admission into the "ring of secrecy" seems to have charmed away the Intelligence and Security Committee's critical faculties.

The ISC has just completed its report on the performance of the intelligence services in the run-up to the bombings of 7 July 2005 and submitted it to the Prime Minister. This will be published "after any deletion of sensitive material" at the end of April. On current plans, other than a "definitive narrative of events" to be prepared by the Home Office, this is all the British people are going to get.

The examination and assessment of the terrible events of July 2005 rest entirely in the hands of politicians and civil servants. The ISC, which consists of nine parliamentarians (mainly Labour and Tory ex-ministers, but including a single peer and a lone Lib Dem), therefore bears a weighty responsibility.

A key weakness is that the senior civil servants who provide support to the committee decide what intelligence it can and cannot see. It is within the ring of secrecy, but with no rights of independent access and no means of knowing what it should know. ISC visits to intelligence installations are usually heavily stage-managed. Crucially, it is not a notably inquisitive body and, despite being cross-party, is generally subservient to the Government. Its report on the September 2002 Iraq dossier gives a flavour of its style:

"We are content that the Joint Intelligence Committee has not been subjected to political pressures. And that its independence and impartiality has [sic] not been compromised in any way."

Nevertheless, the committee could hardly avoid mentioning some of the key issues, in particular the failure of MI5 to develop its surveillance of Mohammed Sidique Khan, who led the 7/7 bombers. MI5's explanation seems to be that it was suspicious of him, and was going to pay more attention to him, but never got round to it.

And the ISC appears to have accepted this and put it down to lack of resources. Four years after 9/11 and two years after our invasion of Iraq, we failed to pick up on the leader of what was to become the most lethal terror plot in London's history because we did not have enough surveillance people.

In a proper inquiry, this would not be a conclusion but a starting point for a vigorous look at how our intelligence services function. Could no resources be found? Why was surveillance stretched beyond breaking point anyway? Is it possible that the intelligence bureaucracy vastly underestimated the increase in the domestic threat as a result of our military intervention in Iraq? Or is it just that they are not very on the ball? Apparently ignoring the threat at a time when the UK was about to host the G8 summit and possibly be awarded the Olympics went against common sense.

We seem content to leave oversight of our intelligence services to a small group of politicians of narrow experience who value avoiding embarrassment more highly than a steely quest for efficiency. Let us hope the practice catches on. We will be close to winning the moment when al-Qa'ida is content to delegate oversight of its operations to its own version of the ISC.

The report, which appears to be designed to dampen down public disquiet at our intelligence performance, looks unlikely to succeed. More likely it will serve as a touchstone to renew and reinvigorate demands for a public or at least an independent inquiry.

Crispin Black is a former government intelligence analyst and author of '7/7: the London Bombs. What Went Wrong?'