Who killed Denis Donaldson, a figure who had moved in the space of three months from being a trusted, convivial adviser to Sinn Féin leaders Gerry Adams and Martin McGuinness at their negotiations with British government officials to a loathed, lonely figure brutally slain at a remote cottage in Donegal?

As a "tout" or informer who passed information from inside the Republican movement to British and Northern Ireland security services over two decades, Donaldson was a marked man – even though his exposure in December 2005 had come at a time when the Irish Republican Army's "armed struggle" was in effect already over, and thus had far less of an impact than if it had occurred at the height of the "troubles".

The politicians in Northern Ireland were quick to condemn the murder, and equally swift in seeking to make it part of their own favoured "narrative" of what is happening and what needs to happen in the current period of political stasis. Sinn Féin and the IRA's repudiation was notably firm, but linked (in the contribution of the party's chief negotiator Martin McGuinness) to a scolding of Unionists for freezing political progress; the Democratic Unionist Party's Ian Paisley Jr was similarly severe in seeing Donaldson's fate as evidence of the Republican propensity for violence.

The question of attribution and of investigation is clearly vital: this is both a political murder and a serious criminal act. My guess (and that is all it is at this stage) is that the deed was done by IRA members embittered by Donaldson's treachery, and meanwhile keen to taunt the Sinn Féin leadership of Adams and McGuinness for their endless preening in front of the TV cameras in pursuance of a "peace process" that is doing nothing to deliver the objectives for which the ordinary IRA volunteers sacrificed so much of their adult lives.

An additional political aim would be to signal to the governments of Bertie Ahern in Dublin and Tony Blair in London that some Republicans remain defiantly outside any tent of "inclusion" and "reconciliation" they can construct.

If dissident IRA members are indeed responsible, this might signal the beginning of the collapse of the organisation's own edifice, which could take place quite quickly and engulf a Sinn Féin leadership that is already finding the reception has got much colder in Dublin, Washington, and even London.

It seems highly improbable that the attack could have been authorised by the IRA leadership. Adams and McGuinness "condemned" the killing, a toxic word they have not used since the Real IRA splinter-group committed the Omagh atrocity in August 1998; this suggests they are serious about their denials of any responsibility (when the Provisional IRA commits a murder but won't admit it, the organisation just says it's "wrong"). And while I think the Real IRA or Continuity IRA would have claimed Donaldson's murder if they had authored it, internal Republican dissidents who had decided it was time to give up on loyalty to the leadership and "whack" the informer would have no reason to identify themselves.

The other candidate suggested for Donaldson's murder – especially in Republican political circles, but more widely among members of the conspiracist tendency which is never short of material in Northern Ireland – is the British intelligence agencies themselves. This too is unlikely, even though they have been deeply involved in some highly unsavoury incidents in Northern Ireland during the last thirty-five years. It may be a Republican conceit to imagine themselves as an Irish equivalent of the African National Congress battling the might of "British imperialism", but since the early 1990s the aim of Northern Ireland's "securocrats" (a term from South Africa's own long struggle that became a Provisional IRA favourite) has been not to crush the Provos but tame them by indulgence.

A road to recovery

The broader significance of Denis Donaldson's end and its aftermath is that it illuminates the condition of Northern Ireland's blocked political culture. The group Healing Through Remembering, which specifically addressing the question of truth recovery and how best it can proceed, proposes an argument relevant to this point: that there can be no real progress until there is a general acknowledgment by all actors of their responsibilities.

As things stand, that is completely lacking. The IRA continues to insist that the "armed struggle" was legitimate, without explaining why those who would want to sustain it now are wrong or why it had to be continued at such human cost for so long; it is presented as an inevitable response to partition but it is a response the vast majority of Irish people eschewed.

The Loyalists insist that the sectarian crimes for which they were responsible were essentially the product of rabble-rousing speeches by Unionist politicians in the early 1970s; this doesn't explain either why most Protestants were unaffected (or alienated) by them or why these speeches had such an enduring effect in the 1980s and 1990s – never mind how ordinary Catholics could at any point have been "legitimate targets".

Robin Wilson is director of the Belfast-based think tank Democratic Dialogue

Also by Robin Wilson in openDemocracy:

"The end of the IRA" (March 2005)

"Northern Ireland peace by peace"
(October 2005)

Democratic Dialogue’s report Recognition and Remembering is here

Britain's Labour government has apologised for the shooting dead of fourteen Catholic civil-rights demonstrators in January 1972, and (at vast expense) established the "Bloody Sunday" tribunal to establish the truth of that contested event. The British and Irish governments have also agreed to a number of inquiries into alleged collusion between elements of the state and Loyalist or Republican paramilitaries. Yet there seems no real appreciation in either government of the fundamental lack of a moral compass in dealing with paramilitaries, which has alternated over the years between repression and appeasement, in each case at the expense of the rule of law and the emergence of something akin to a normal civil society.

In this light, and as I argued in openDemocracy in March 2005, it really was the McCartney sisters' campaign for the rule of law after the vicious murder of their brother by a Sinn Féin member in Belfast which brought closure to the IRA campaign, something that neither mighty state had managed to do in decades.

There are other institutions in Northern Ireland, such as the churches and the media, which have much to gain and to contribute by facing their own responsibilities for sustaining sectarian mindsets and the associated antagonism. There are also issues of "sins of omission", which would apply to large swathes of the (particularly Protestant) middle class, who hid behind their garden fences rather than put their heads over the parapet during three decades of bitter conflict.

Northern Ireland still has to find the spaces, places and institutions of dialogue where its people can speak and listen honestly to each other as part of the search for a full accounting of what they have done to each other, and what they have endured, during the "long war". This profound moral as well as political dilemma will remain long after the name of Denis Donaldson is added to the melancholy roster of "lost lives".