Our reportage on the declassified government files from the 1990s reveal that civil servants were telling Sinn Fein as early as 1995 that decommissioned weapons might not be tested.
This would make it far harder to prove terrorist usage of the weapons in shootings. Last year the then PSNI chief constable George Hamilton said no tests meant police investigated with “one hand tied behind our backs”.
It is striking to learn that this assurance was being given to republicans as early as 1995, the year after the first IRA ceasefire, and well before Tony Blair’s government came to power.
Mr Blair has sometimes been accused of always seeking to appease Sinn Fein, to keep them in the political process. In fact, the decommissioning legislation that prevented forensic testing was passed in 1997, before John Major left office.
It is not hard to understand his logic. He said that his main concern was that the weapons were put beyond use.
The problem comes with the context, which is twofold.
In a grave abuse of the goodwill the UK showed in talking to republicans, just after a long terror campaign, the IRA returned to violence in 1996, with the Canary Wharf bomb and later murders such as that of two RUC men in Lurgan.
It is not unreasonable now, in light of these apparent reassurances from London, to speculate that the IRA sensed British weakness before it broke its ceasefire, and that it was calculating that one further push of terror would get results.
The 1995 revelations about forensic testing are telling in another way. They show that from the beginning the British state, via a Tory then a Labour government, was trying hard to make things easy for the IRA if it repudiated terror.
If they thought Irish nationalism would in return show goodwill with regard to the past, they have had a reality check in recent years, amid ever growing distortions of collusion, trials of low ranking soldiers (while IRA leaders so far have avoided the same) and a proposed category of legacy investigation that means the RUC alone will face misconduct probes.