A Historical Murders Unit for Northern Ireland risks repeating the scandal of the Historic Allegations Team on Iraq – which saw Philip Shiner struck off the roll of solicitors over misconduct relating to false abuse claims against British troops.  But it would also have peculiar features of its own.  Some of the incidents likely to be investigated took place the best part of 50 years ago.  The Government has a duty to weigh how probable it is any retired soldier eventually hauled before the courts would get a fair trial, given the interplay between the passing of time and the fallibility of memory.

More fundamentally, there would be an injustice at the heart of the exercise.  British troops were professional soldiers serving in the armed forces, with their formal structure of records, chains of command, disciplinary codes and regiments.  Republican or loyalist terrorists were not: soldiers putting their lives on the line, in order to protect civilians of all religions and none, are not comparable to fanatics who sought to maim and murder on a sectarian basis.  There can be little doubt that the weight of investigations and potential prosecutions would fall on former British servicemen, in some cases long retired after risking their lives for their country.

This is would be an unfair treatment of the past with serious implications for the future – that’s to say, on recruitment to the armed forces.  That one might later be hauled before the authorities – to be cross-questioned amidst the order of a courtroom by lawyers with no experience of serving under fire about a split-second decision made years before, amidst the chaos of armed conflict – is not exactly an incentive to serve.  Michael Fallon has called for any investigation not to probe old, unproven claims without new evidence, and to make a distinction between soldiers and terrorists.  He also supports a statute of limitations – a time limit on any enquiries.

This is the nub of the matter.  The former Defence Secretary has claimed that “the Cabinet has gone wobbly” on such a statute.  It isn’t hard to see why.  Karen Bradley wants to get an Executive back together again in the province.  She will also be mindful of the current tensions between the British and Irish Governments over Brexit and the border. The Northern Ireland Office is scarcely a spokesman for Sinn Fein – one of the main drivers of an investigation – but it must deal with the party: that’s part of its brief.  Downing Street, meanwhile, will be especially concerned about the position of the DUP.

That party is perhaps less focused on the likely injustices to former solders that would arise from any process than the prospect of it going after former IRA terrorists.  So the DUP is against a statute of limitations, it is sometimes claimed. This is not quite right.  The party’s position on such a statute is a bit like its stance on the Customs Union.  It wants Northern Ireland to be treated in the same way as the rest of the UK.  This opens up a potential way forward.  The Ministry of Defence is mulling how a statute of limitations with wider application might work – one that would reach back beyond the 1970s and possibly forwards to the Afghanistan and Iraq conflicts.

Such a time limit could be applied to Northern Ireland without it being specifically drawn up to apply there.  It would offer a way round the Cabinet tensions of earlier this week, when Gavin Williamson, David Davis, Boris Johnson and Liam Fox all opposed the exclusion of a statute from a consultation that the Government is due to launch on historic allegations about the Troubles.  It would be very painful for the relatives of those murdered by loyalist and republican terrorists to see such a UK-wide statute introduced.  But such a course would be for the best.  Few things madden voters more than former servicemen being unjustly pursued.