The allegation that the British army had an informer in the top echelons of the IRA for many years is a reminder that states confronted with paramilitary insurgency, otherwise known as terrorism, respond in several different ways - and with several different moralities.
Military and political responses are accompanied by intelligence and counter-intelligence operations. These rapidly develop a momentum of their own, raising profound questions of accountability and legality. Even in conventionally declared inter-state wars rules of engagement apply. How much more should this be the case in the war between British security forces and the IRA, fought out over three decades.
The fallout, in a liberal democratic society, has necessitated searching investigations, such as the Saville Inquiry into Bloody Sunday and that of Sir John Stevens into police intelligence collusion with loyalist killers. The questions of morality and procedure raised by these latest developments seem much more serious. How far does state security override established legal and moral rules in the interests of defeating such a determined enemy?
It is surely the mark of democratic civility that clear guidelines should be established and laid down to define such boundaries in advance. But this is normally put in place after the event, when the war is over or politically resolved. Thus there is some comfort that the revelations about the alleged British agent who led the IRA's security unit, Alfredo Scappaticci, operating under the sinister codename "Stakeknife", may indicate that the "end game" is in play.
Even so, a whole series of separate questions arises on the timing of this affair so soon after the collapse of negotiations about restoring the devolved government and the postponement of the Stormont elections. Who benefits from these stories about murderous discipline against informers conducted by the man who was reportedly the principal informer? Who bears responsibility for the line of command in which many innocent victims were killed? Do they discredit both the IRA and the British army equally in such a way as to facilitate political progress? Political pressure, further reportage and, presumably, public inquiries into the legality and morality of such a dirty war will help answer these questions. It is all too easy to react with world-weary realism towards the horrifying details of such a ruthless campaign.
Responsibility comes after the event, it is said: legality cannot apply when a state is confronted with such a deadly enemy. Democratic politics cannot succumb to such amoral temptations of power without losing its own credibility in launching a dirty war. That is why there must be a full accounting for what happened both within the United Kingdom and in its relations with the Republic. Truth and reconciliation go together. These matters must engender efforts to restore the political process and the institutions.