When a new James Bond film hits the screens, an expert is wheeled out to opine that 007's "licence to kill" is fiction, like the agent. Yet for real-life spooks, a licence to kill, torture, lie and dissemble seems to go with the job.

The murder of a human rights lawyer in Belfast involved the collusion of the British state, a report by a former war crimes prosecutor has concluded, 30 years later. Next it was announced that the Government was to pay more than £2m to the family of a Libyan dissident abducted with the help of the British secret service and flown to Tripoli where he was tortured by Colonel Gaddafi's secret police. The British government admitted no legal liability but the huge payment spoke for itself.

So we've paid a whacking sum to Sami al-Saadi and owned up over the murder for Pat Finucane – one very British stitch-up after another. The Hillsborough police cover-up and Jimmy Savile scandal also showed how institutions close ranks rather than root out bad behaviour from their midst. At the heart of British public life there so often seems to lurk something secret, unaccountable and apparently irreformable.

The classic defence for all this is "a few bad apples" low down the blame-chain. But collusion in Ulster was widespread. And British involvement with the Americans flying people off to foreign lands where they can be tortured out of sight goes to the highest levels of MI6. Perhaps higher.

The human rights of al-Saadi and another Libyan dissident, Abdel Hakim Belhaj, were fair game because the two Islamicists were suspected of links to Osama bin Laden. There was no way of verifying such claims but evidence does not need to be tested when justice is dispensed in secret. It was the same in the dirty war in Northern Ireland. Finucane had Republican sympathisers in his family and defended prominent IRA suspects. That was enough.

Yet there is a myopic short-term memory syndrome involved in the idea that state operatives can act with impunity because no one will care when the truth comes out 30 years later. Abdel Hakim Belhaj, whom we had strung up by his wrists, later became a British ally as a leader of the rebel forces who toppled Gaddafi. Former IRA leaders are now our partners in the trust- and confidence-building process on which peace in Northern Ireland rests, if shakily.

It is still unclear how high up the Finucane plot went. Nor have we uncovered the full truth of British complicity in foreign torture rendition. A police investigation is under way, as is an inquiry by a retired judge into Britain's mistreatment of terrorism suspects since 9/11. But a culture of deniability is built into the British establishment.

Ministers didn't know about the plans to murder Finucane only because they had set up a system that distanced themselves from the dirty work, much as rendition for torture did 30 years later. And now ministers want, on Tuesday, a vote to insist evidence in cases involving national security is given in secret. I don't think so.