The revelations from Libya show just how far we are from touching the bottom of British complicity in rendition and torture. For anyone who had hoped that, 10 years on from the catastrophic attacks on the United States which kicked off the "war on terror" we might be starting to come to terms with the abuses carried out in our name and put them behind us, the depressing news is that we seem to be further than ever from doing so.

With the caveat that these documents have yet to be fully verified, it would appear that we have been given yet another insight into our own security services getting mixed up in some of the truly appalling abuses carried out by an odious regime.

So far we have read of British intelligence services cheerfully assisting in the rendition of a suspect, along with his wife and children, back to Libya, where they must have known about the horrific treatment opponents of the regime could expect.

And we have seen our relations with anti-Gaddafi forces poisoned virtually before they could even begin, with the new security commander in Tripoli threatening to sue MI6 and the CIA for what he alleges was their role in the years of torture he suffered under the old regime. Leaving aside the terrifyingly unpredictable face Britain must present to the world – collaborating in your torture one year and bombing your enemies the next – a key sentence stands out in what Abdul Hakim Belhaj has said about his ordeal: "[I was] surprised that the British got involved in what was a very painful period in my life."

First, it sits in stark contrast to what the CIA has said about the revelations in these documents – that it "can't come as a surprise that the Central Intelligence Agency works with foreign governments to help protect our country from terrorism and other deadly threats". But more important, it shows exactly what we are at risk of losing if we continue to allow our security services to behave in the way they have done and fail to properly hold to account those involved in what happened.

People like Belhaj – and the vast majority of the British public, who find such practices abhorrent – have expressed surprise or shock that our services have been involved in the abuse of detainees. So unless we want the UK to become the kind of place where allegations of torture are met with a shrug, rather than a storm of condemnation, we need to see real action to ensure this never happens again.

This has to start with a proper inquiry, with real teeth, into the complicity of British personnel in rendition and torture. Sadly the setup for the Gibson inquiry, which is yet to commence, will not provide this. On its current lines, the inquiry lacks clout, being unable to compel the attendance of witnesses or provision of evidence; it lacks independence, with David Cameron and the head of the civil service having the final say on what, if anything, will be made public; and it lacks any meaningful way for those who have been victims of torture – and are therefore also key witnesses – to participate, and argue their side of the story.

The sad but inescapable fact is that it is hard to see any way by which the Gibson inquiry could have uncovered the evidence we have seen from Libya in the last few days: it will be reliant on what the security services choose to hand over, rather than being in a position to dig out crucial evidence itself. Moreover, we have already heard from the inquiry that it does not intend even to approach foreign personnel for evidence, thereby knocking out the chance that it would have asked for information of this kind from the Libyans or the CIA.

We have heard foreign secretary William Hague emphasising that the allegations "relate to a period under the previous government", but the uncomfortable fact remains that they are still a problem for this one. Given Hague's admission that he has "no knowledge … of what was happening behind the scenes at that time", one would hope that he would be more keen than anyone to have an inquiry which can really get to the bottom of this.

There is still time for ministers to change track. We shouldn't have to rely on the toppling of dictators to find out what abuses our own services have been involved in. Only a properly independent inquiry with real clout will let us find out on our own terms, and hold people accountable before this is allowed to do any more damage to Britain's international reputation.