The Sunningdale negotiation in 1973 was prolonged by at least 24 hours because of a triangular confrontation between Brian Faulkner, John Hume and Ted Heath. The row centred on the hypothetical circumstances under which control of policing might eventually be devolved to a Northern Ireland power-sharing executive.
In the event, this issue totally failed to surface in the maelstrom of controversy after the signing of the agreement. Brian Faulkner had misjudged the sensitivities of those he represented.
But the factor that destabilised Faulkner turned out to be the wording of the clause on de facto recognition of Northern Ireland by the Dublin Government. He had failed to push for modifications that Dublin might have felt obliged to concede under pressure. For in preparing for this conference, the government had pulled back from a more generous wording of this recognition clause, to which it might have been forced back by a more vigorous unionist reaction.
It has to be said that even our less forthcoming wording was successfully legally challenged by Kevin Boland - and it was in fact our minimalist defence of this wording that finally ing Faulkner's presentation of the agreement to unionist opinion.
There may have been a similar unionist miscalculation in Belfast a year ago. Since February 1995 the UUP had chosen to make a big issue of some intrinsically unimportant aspects of the Framework Agreement relating to the three strands - Internal, North-South and East-West. In order to get off that hook, it dramatised this issue at the outset of the Holy Week negotiations by means of John Taylor's announcement that the party would not touch, with a 40-foot bargepole, the proposals that had been put forward in relation to the three strands.
By taking this line at the start of the week, the UUP clearly judged it would eventually succeed in getting changes in the three-strand proposals, which it could then present to its supporters as a victory that would justify its agreement to a settlement. The trouble with this approach was that it involved using up negotiating ammunition on what was largely a self-manufactured problem of relatively limited significance.
Its tactic in the talks was to keep all its cards close to its chest until the evening of Holy Thursday, when its negotiators sought and secured some changes in the three-strand proposals. They failed to realise that their "success" on this issue at a late stage would give Sinn Fein an uncovenanted advantage by providing that party with an excuse to come in after the unionists on what it saw as crucial issues highly sensitive to unionists, such as early prisoner releases.
At the time, the choreography of this part of the negotiation was sufficiently clear to an outsider like myself to have enabled me, in discussion programmes on RTE and BBC TV, to predict that Sinn Fein would inevitably gain concessions.
On Good Friday the outcome of this final round of negotiations with Sinn Fein gave the UUP a grave dilemma. It had to choose between collapsing the agreement at the very last moment, thus incurring worldwide odium, or accepting a fudged presentation of the decommissioning and executive issue.
Tony Blair's last-minute "sideletter" to David Trimble gave the UUP leader something to wave in support of his decision to accept the agreement. But that little drama was bound to cause serious trouble down the road, for David Trimble's overstated interpretation of that letter claimed the achievement of a decommissioning precondition that the agreement did not in fact contain.
But, in a sense, Sinn Fein also trapped itself with this tactic, for it was inevitable a subsequent attempt by it to stand on the pure letter of the agreement would create an impossible situation for everyone else. The Sinn Fein leadership led itself, or at any rate its members in and outside the IRA, into believing not merely that it could enter the executive before starting decommissioning, but that it could do so before even agreeing a process of decommissioning.
Clearly, just as UUP members were led to believe decommissioning would precede the establishment of the executive, so IRA members were led to believe nothing need happen about decommissioning until much later, perhaps after they had seen the outcome of the post-Patten RUC reforms.
IRA members may even have deluded themselves into thinking they might not have to decommission at all, and all that needed to happen eventually would be for Sinn Fein formally to ask the IRA to destroy its arms and then to report that this request had been refused.
Certainly the IRA allowed itself to be misled by this negotiating outcome into believing that nationalist public opinion, North and South, and the Government would continue to support Sinn Fein participation in the Northern Ireland executive even in the face of advance announcements by the organisation that there would be no decommissioning at all.
This was a serious miscalculation, into which Sinn Fein/IRA was led by the success of its leadership in the negotiation of the wording of the decommissioning provisions of the Belfast Agreement.
Ought the two governments to have accepted an agreement involving a fudge that would inevitably lead both sets of negotiators to make claims to their members that could not eventually be sustained? Clearly not; ideally.
But on Good Friday afternoon last, the two governments were not ideally placed. The choice for them must have appeared to be either a fudge or no agreement at all. And clearly it was better to have an agreement with a fudge that might somehow be sorted out down the line, than to have no agreement at all. I cannot say that had I been in their shoes I would have acted differently
At present we cannot know whether this black knot can successfully be untied. What is clear is as long as the IRA fails to modify its intransigent statements, there will simply be no decommissioning. In the face of that kind of negative stance, the absolute minimum needed for progress is some kind of timetable for decommissioning over the remainder of the agreed two-year period, ending in May next year. Without that, nationalists or unionists cannot reasonably be expected to serve in an administration with Sinn Fein.
Whether such a move would be sufficient to enable David Trimble to lead his team into the executive without at least an initial destruction of arms or explosives coinciding with the establishment of the executive is another matter. But, whatever about that, the ball is now squarely in Sinn Fein's court.
For any moral advantage it may have enjoyed by relying on the letter of the agreement has been lost by the intransigence of the IRA's repeated rejection of any decommissioning.
Gerry Adams and Martin McGuinness must be aware of this. They have shown leadership in guiding their movement towards an exclusively peaceful path. But they must know that the success of their whole peace strategy is currently being undermined by this IRA stance. Their own interest in the implementation of the agreement requires that they now move their colleagues away from the untenable position they have adopted.