The immediate threat to the Belfast Agreement appeared to have receded last night. However, hopes for a speedy breakthrough, a resolution of the decommissioning issue, and the establishment of the Northern Ireland executive, appeared slight, even as the Taoiseach and the British Prime Minister finished a long day of negotiations at Hillsborough Castle.
Neither Mr Blair nor Mr Ahern would quit while they believed there was further progress to be made. And hours of very direct, very tough talks separately with Sinn Fein, the Ulster Unionists and the SDLP had apparently convinced them there was, and is, something to play for. However, British and Irish officials appeared increasingly inclined to share the Ulster Unionist view that the game would not, in all probability, be concluded this week.
Sources close to the Prime Minister, who 24 hours earlier described speculation about a further extension of the deadline as "somewhat premature", last night conceded it seemed "more likely."
And despite Mr Seamus Mallon's determined optimism that the two leaders could deliver a result some time today, Irish sources, too, appeared convinced considerably more time would be needed to effect the long-awaited breakthrough. The immediate decision facing Mr Ahern and Mr Blair at the halfway point last evening was whether to continue talking through the night, or to adjourn and head home.
(Mr Blair would in any event almost certainly want to be in the Commons this afternoon for the last Question Time before the Easter recess, to answer questions and give MPs an up-to-date assessment of the Kosovo crisis).
At this writing it was unclear whether both leaders might opt for a full-scale adjournment until some time after the Easter holiday. The encouragement appeared to be that the question was one of possible adjournment, rather than the predicted "soft landing" leading to "parking" and, in effect, to a protracted suspension of the Belfast Agreement.
It could still come to that. But the impression is firmly abroad here, sustained by both British and Irish assessments, that some progress has been made, and that a serious engagement on the crunch decommissioning issue has at last begun.
However, the extent of that engagement, and the success of Mr Blair and Mr Ahern in yet establishing the "bottom line" positions of the two key parties, Sinn Fein and the Ulster Unionists, remain unclear.
And in a cautionary tone, one well-placed source last night dismissed much media and press speculation on the likely specifics of various canvassed "solutions", as still significantly ahead of the reality. Mr John Taylor, the Ulster Unionist deputy leader, moved forcefully last night to quash reports that his party was prepared to enter the executive in return for some IRA decommissioning within a period (unspecified) of weeks.
Those who suggested this, he said, were deliberately misrepresenting the position of his party. And while many close observers of this process have fond memories of the "barge pole", with which Mr Taylor amused journalists this time last year with his assessments of the chances of an agreement, a day spent canvassing the state of UUP opinion at Stormont readily explained the ferocity of his response.
It was, it seemed, a variation of a theme which, elsewhere, had Mr Blair pressing Mr Trimble to at least agree the creation of the executive in "shadow" form, in return for a post-dated promise of some subsequent decommissioning.
Sources close to the UUP leader yesterday insisted that the Prime Minister had not put such a proposition to him.
In the same spirit, one official insider said he would be perfectly happy with the latest reported compromise, namely that a date might be set, some weeks hence, for the simultaneous creation of the executive and the start of IRA decommissioning.
The only reason for his slight scepticism, he explained, was that such an arrangement could have been effected at virtually any point in the past year, had the relevant parties been agreeable.
Another source close to the negotiations last night resisted an invitation to sketch possible scenarios, insisting that the issue remained "more fundamental than sequencing."
Choreography, he explained, was easy enough to devise, provided the principals wanted to dance. So do they? At this writing two things seemed clear.
One, that the Ulster Unionists were sticking firmly to their requirement for an actual start to decommissioning as the price of Sinn Fein's entry into government, and for "product" as a start to "process". And two, that the pressure at this point is more directly aimed at Sinn Fein.
There is a continuing belief in SDLP circles that some variation of "the Mallon plan", requiring agreement that decommissioning will happen, defining the methodology by which it would be processed, and the date by which it would be accomplished, could yet force the Ulster Unionists off their "absolutist position".
Ulster Unionists yesterday maintained it would not. And some borrowed from Mr Gerry Adams's language about the need to ensure he and Mr Trimble were "both in the loop" to suggest an actual bottom-line requirement that they should indeed "jump" at the same time.
In any event, the contented view among Mr Trimble's Assembly members appeared to be that they would come under no significant pressure while the republican movement continued to resist the concept of decommissioning even as "an obligation" under the terms of the Belfast Agreement. The republican movement has until now vigorously rejected decommissioning as either a precondition or an obligation under the terms of the Belfast Agreement.
Acceptance of it would mark a dramatic shift in their position. But even if Mr Ahern and Mr Blair had brought them to that point, the view in Belfast last night remained that agreeing the terms and conditions for meeting it would take more than a week, let alone a day.