Two questions face the deputy Director of Public Prosecutions for Northern Ireland when deciding whether or not to instruct the police to charge Gerry Adams with a crime. Is there enough evidence? And is it in the public interest to pursue a case against him?
Some media reports suggest that the charge which the police wish to bring is one of IRA membership. Presumably this means past IRA membership – given that the evidence being assessed includes the Boston College archives and Adams's own writings.
I think that anyone reading the books of Gerry Adams would not even ask if he was in the IRA. He has been coy, but he has not been very coy.
He tells us that he was sent for by Liam McMillen on August 16, 1969 to help in the defence of the Falls. Liam McMillen didn't send for me and, if he had, I wouldn't have given up a job to rush to his side.
But Adams took orders from him, and Mr McMillen was the officer commanding the Belfast IRA at the time, which is not disputed by anyone.
Adams was on an IRA delegation to meet William Whitelaw in London in June 1972, and released from internment for that purpose.
When feuding broke out between the Provisionals and the Official IRA, Adams was appointed by Billy McKee, then Belfast commander, to negotiate a truce.
Again, McKee didn't ask me to do that and, if he had, I wouldn't have been much use, because no one would have believed that I could have made commitments on behalf of the Provisionals.
When arrested again Adams was in a meeting in a house on the Falls Road with Brendan Hughes and Tom Cahill and other members of the IRA brigade staff. Was he making the tea for them?
And, when he was in Long Kesh, he was immediately put to planning escapes and chosen as one of those who should be helped to get away.
Now, if I had been in Long Kesh, I don't think the Provos would have entrusted me with their escape plans, or selected me as a primary beneficiary of them.
And one could go on. In other words, Adams is right to say that he does not dissociate himself from the IRA. All he does is tell people, if they ask, that he wasn't a member. But, if you ask no questions, you get told no lies.
It annoys unionists that he denies his membership, and it annoys some republicans even more, because, as Brendan Hughes said, it passes responsibility for the blood-letting away from him and on to them.
But, on the key question of whether a successful prosecution for IRA membership in the past could be brought against Gerry Adams, the answer is probably yes. Then there is the question of whether it is in the public interest.
First of all, it would seem gratuitous and malicious to charge him with IRA membership alone. That could have been done at any time in past decades and there was good reason for not doing it. That reason was to spare the peace process, to keep the man in play.
Given that everyone in the peace process understood that implicitly or otherwise, then choosing to hit him with the charge now seems pathetic and indulgent.
It is one thing to secure a conviction for murder or directing acts of terrorism, but a mere membership charge – after making use of the man's integral role in the republican movement to negotiate a political deal, which he wouldn't have been able to deliver if he hadn't been operating at the top tier – would seem vengeful; a breach of faith, even.
But there is another public interest consideration. Having arrested Adams and come under political pressure not to charge him, there is a public interest in avoiding any suggestion that republicans have a dispensation. It is not only the sensitivities of republicans that have to be considered, but those of unionists too.
And they believe that Adams may be untouchable; that Sinn Fein operates on an assumption that its own people should be exempt from prosecution. They have received some endorsement of that idea through the on-the-runs scheme.
The credibility of the policing and justice system itself is a public interest. If the deputy DPP were to announce now that evidence did exist, but that, in spite of that, no prosecution would be taken for public interest reasons, then those reasons would have to be explained. And they would have to be strong.
And it is likely that the logic would be extendible to others. Unless there is a public interest in avoiding all pre-1998 cases, a decision like this in favour of Adams would appear prejudicial.
Charging him would make it easier to charge, for instance, the Bloody Sunday Paras. Waiving a charge for which there was evidence would expose any further prosecutions like those to dire criticism.
So, it's a fine mess the DPP is in. Either present Adams with a charge which will seem petty and vindictive, or advance by one very big step the argument for a general amnesty.