The existence of a separate Attorney General for Northern Ireland dates back to the start of its devolution settlement in 1921.  This is a reminder that the post has its roots in the unionist tradition there: it’s not some newfangled arrangement dreamed up to appease nationalists, republicans, and Sinn Fein in particular.

Out went the post with the abolition of Stormont in 1972, and back it came in 2010 when justice was devolved to the Northern Ireland institutions. Though with a twist: under the old dispensation, the Attorney General was a Ulster Unionist politician.  Now, this judicial function is separate from the executive and legislature.

In other words, unionists and republicans alike agreed to the arrangement, which is thus an integral part of Northern Ireland’s delicate political settlement.  Opposed on the national question, they are united on the devolution one – most of the time, both ask for more. Were this brick in Northern Ireland’s edifice suddenly to be dynamited, the whole structure could come down, with baleful consequences.

That abstract possibility has a raw presence this morning, in the aftermath of Johnny Mercer’s sacking as a Defence Minister.  He had planned to quit in any event because, as his departure letter made clear, he believes that veterans who served in Northern Ireland should have had the protections that those who served elsewhere have been given in the Overseas Operations Bill, of which he had charge.

Mercer was right to suggest in that letter that new evidence, in relation to allegations of crimes by members of the armed forces during the Troubles, should spur investigations and, if necessary prosectutions – and add that until or unless this is produced, the vexacious pursuit of veterans who served their country, and had to take snap decisions in dire circumstances while doing so, should stop.

The question is how to do this without upending the settlement in Northern Ireland, and peace with it.  Solutions have been floated.  This site has amplified one, which would draw a distinction between members of our armed forces and those of terrorist gangs.  It was floated by Jonathan Caine, who served no fewer than six Conservative Northern Ireland Secretaries as a special adviser.

His starting-point was that “there is no moral equivalence between someone who sets out to do his or her duty upholding the law, but who in the course of that duty might discharge a firearm with possibly fatal consequences, and the action of someone who deliberately sets out to commit murder”.

Having established that, Lord Caine (as he now is) proposed that investigators focus “not on what clothing people wore but on what they did”, recommending that “no investigations or proceedings into suspected Troubles-related offences could commence or continue without a certificate being issued by a senior legal figure”.

Such a certificate could only be issued “if that legal figure were to conclude that a person potentially under investigation or facing trial had not honestly believed that the action he or she took with lethal or injurious effect was reasonable in the circumstances”.  He pointed out that one wouldn’t need new laws to make such a change – a topical consideration given the circumstances of Mercer’s resignation.

This certificate-based system wouldn’t have required additions to the Overseas Operations Bill.  Nor would the “simultaneous legisaltion” to which Mercer refers in his letter be needed.  It would be “based on a modified application of Section 3 of the Criminal Law Act (Northern Ireland) 1967 and the common law on self-defence”.

Finally, it wouldn’t put the nose of John Larkin, Northern Ireland’s present Attorney-General, out of joint – because he proposed the change himself “in a recent lecture”, Caine pointed out in 2019.  Furthermore, the scope of the Human Rights Act could be limited so as not to apply retrospectively to acts that occured many years before the Act itself came into force.

Why hasn’t the Government taken this proposal up?  It’s been hinted to ConHome that some Ministers think it goes too far – and are wary of explicitly drawing a distinction in the way that investigations operate between the treatment of former members of the armed forces and of terrorist gangs.

Why didn’t Mercer?  His departure letter focused broadly on what Boris Johnson hasn’t done; it didn’t spell out in detail what he should actually do.  But it’s clear that if Ministers think the Larkin and Caine ideas go too far, Mercer thinks that they don’t go nearly far enough.  His friends confirm he believes that “simultaneous leglislation” is the only reliable course.

In essence, Mercer’s solution, his friends suggest, is to grasp the bull of Troubles-related offences by the horns, and legislate to prevent Northern Ireland’s Attorney General from undertaking investigations and its Director of Public Prosecutions from implementing prosecutions.

The heart of the matter is that he is willing to risk the collapse of Northern Ireland’s settlement in order to gain protection for armed forces veterans.  The recommitment of the army to the Province were that to happen, with all the risks to soldiers’ lives and safety that such a move would entail, could duly follow.  Northern Ireland’s bull can indeed be grasped by the horns, but what happens if it runs wild?

Boris Johnson was never likely to follow such a course, and the responsibility to find a way forward is no longer Mercer’s: it’s his.  If the Larkin plan is out, and the Mercer plan is out, what exactly will he do?  Downing Street stresses that a solution will be found.  We suspect that he doesn’t know where to turn next.

This story of a would-be resignation and an actual sacking is a sad one.  Mercer put his trust in the Prime Minister, backing him in the 2019 leadership election.  Johnson returned it by appointing him as a Minister – not to any old job (we believe that Mercer would have turned down such offers), but to take responsibility for veterans, whose cause fires his passion for politics.

It isn’t wisdom after the event to write that it was always possible, if not likely, that this story was never going to end well.  It closes with friends of Mercer accusing the Whips Office of betraying a private discussion and leaking his resignation plan, in order to destroy his timetable and force his sacking if necessary.

He wanted to see his Bill through, rightly believing that it offers some service people some protections, and then quit, to make his case for that “simultaneous legislation”.  But the people who matter most are less present politicians than those former soldiers: as Mercer put it in hauntingly in his letter, veterans are “being sectioned, drinking themselves to death and dying before their time”.