On one reading, that was the role played in Belfast yesterday by the former US senator George Mitchell, when he delivered his international body's report on arms decommissioning. For some hours, it seemed the logjam might be easing, until John Major's announcement of plans for a local election sent tensions rising again.
Mr Mitchell is no magic-maker. As he said at the outset of his report, the factors on which a peace process must be based were already known. He did not discover or invent some new element to transform the situation; he simply brought to the problem a measure of American can-do pragmatism.
In that sense, his role was less one of divine intervention than empirical observation, followed by practical suggestions and comment.
He eased the British government off the hook of its long-standing insistence that republicans deliver up arms before being allowed to the table. He did so simply by pointing out that there was no chance of the IRA or the loyalists decommissioning weapons in advance of talks.
The dogs in the streets of Belfast and Dublin already knew that, but the fact of Mr Mitchell saying it has somehow made it more acceptable - or at least tolerable. The same dogs already appreciated the other facts laid out in the Mitchell report, yet somehow he and his two colleagues have clarified many points, made them easier to digest and separated off what is politically possible from what is not.
None of this is accidental, for it is apparent, both from the report itself and from his performance at his news conference, that Mr Mitchell is a class act. With grace and humour, he showed himself to be the most skilful political performer seen in Belfast since - well, since last month, when his friend Bill Clinton was in town.
The British and Irish governments, when they agreed to set up the international body back in November, gave it what seemed a fairly narrow remit, asking for a report on decommissioning. What they got was a report that represents an overview of almost the entire spectrum of the immediate issues.
The international body clearly took as its starting point not the essentially technical issue of decommissioning but the much broader approach of working out how to advance the peace process. It first concluded that no guns were going to be forthcoming in the immediate future, and then moved on to draft a list of democratic principles to which all parties should be required to subscribe.
The IRA, it will be remembered, declared a "complete cessation of military operations" in August 1994 but has always declined to use the word "permanent" in relation to its ceasefire. That word does not appear in the six Mitchell principles, but together these would represent a complete farewell to arms. The deal is that if the IRA insists on not handing over weapons it must instead make a solemn promise to the world that the shadow of the gunman has gone.
Though brief, the report contains mentions of (though not recommendations on) matters such as the prisoners' issue, the use of plastic bullets, the idea of a review of more than 100,000 legally held weapons, and the predominantly Protestant make-up of the RUC. It also mentions "an elective process" - much to the relief of Mr Major, who had been banking on that.
The British government had already done much work on the idea, and Mr Major yesterday spoke of urgently putting legislation through Parliament. The attractions of an election for the Government are obvious, mainly because it will go a fair way to meeting the requirements of the Ulster Unionists.
The Government's enthusiasm arises mainly from the fact that the Ulster Unionist leader, David Trimble, had expressed his opinion that an election would give Sinn Fein a mandate that would allow him to talk to them, even without the decommissioning of weapons.
This opened up the possibility of inter-party talks without an arms hand- over, a route the Government has gratefully taken. Mr Trimble had envisaged an election to a new assembly, but in the Commons yesterday Mr Major seemed to envisage an election of negotiators rather than a plan to set up a devolved institution along parliamentary lines.
This distinction is crucial. Previous assemblies, the longest-lived of which was the Stormont parliament from 1921 until 1972, are still seared into Irish nationalist folk-memory as bastions of Unionist privilege and anti-Catholic discrimination. It is no exaggeration to say that a return to anything reminiscent of this would cause large numbers of republican supporters to contemplate going back to war.
Sinn Fein had a good morning yesterday with the launch of the Mitchell document, but a bad afternoon when John Major lifted the election idea from the obscurity of the report's penultimate page.
But it has now been elevated to the centrepiece of the peace process, where it is destined to remain for some time yet. Even with the promise of Labour support, it will clearly take months for the election idea to be discussed and make its way on to the statute book, and for voters to go to the polls.
This means the abandonment of the present target date for all-party talks to open at the end of next month. Mr Trimble's evident pleasure at the Government's action has also inflamed the suspicion - never far from the surface of the nationalist psyche - that Mr Major's new course was at least partly motivated by the hope of securing Unionist support in the Commons lobbies.
Whatever the truth of this, Sinn Fein find that, 16 months on from the IRA ceasefire, the doors of the conference chamber remain closed to them. The ominous importance of this is that they have elevated the question of all-party talks almost to a point of principle, reassuring their hard men that they would soon get to the table.
Thus a day that began with what looked like a breakthrough ended in something close to crisis, with no easing of the long build-up of frustration within the republican movement. The Mitchell report mentioned the lack of trust in Northern Ireland: the day ended with less trust than ever, and a sense that resolving the election controversy might need the appearance of yet another deus ex machina.Reuse content