It will take some time for last night's wave of severe disappointment to work its way through the political system; but when it does the likelihood and the logic is that everyone will still be working to Plan A - the Agreement.
Last night's Ulster Unionist rejection of Mr Blair's best efforts to settle the business of decommissioning has dealt a damaging blow both to the political agenda and the general political spirit. This is a dark moment for the peace process.
Yet none of the pro-Agreement elements, and these include London, Dublin and most of the Northern Irish parties, have concluded that the Agreement is dead and that everyone must troop despondently back to the drawing board.
Rather, the sense is that there must be at least one more try, and possibly more than one, before the accord has to be written off as a dead letter.
This is partly a matter of emotion, in that so much hope has been invested in the Agreement. But it is also a matter of political logic, for at least three good reasons. One is that, while last night unquestionably represented a blow, the feeling lingers that agreement may not have been a million miles away, and that with a bit more luck and a bit more judgement, success might have been snatched from the jaws of defeat.
Second, this is not just any old agreement: it was put to referendums in both north and south, where it received strong support in both jurisdictions. Last night's 15-minute meeting of the Ulster Unionist Party executive may, for the moment, have halted the Agreement in its tracks, but it has not swept aside that unprecedented democratic endorsement.
The third reason is that, while Unionists and republicans remain completely at odds on the decommissioning issue, the Agreement covers an extraordinary amount of ground in other fields.
It pretty much settled the constitutional issue that caused so much trouble for so many decades, enshrining as it did the principle of consent.
It also laid out the hope of a demilitarised future, setting up reviews of policing and criminal justice. It set up new human rights and equal opportunity institutions, mapping out an equality agenda for a new society.
Technically, all this could now be thrown back into the melting-pot, since the failure to resolve decommissioning means the central institution of this new political geography, the Belfast Assembly, cannot now function as it was meant to do.
Yet so many of these issues were in contention for so long during the Troubles that the two governments and most of the parties will share a profound instinct to save and shelter as much of it as they possibly can. The idea of starting all over again with a clean slate on these issues is almost unthinkable.
Rather, the approach is likely to be to salvage as much of it as possible. In other words, an attempt will be made to keep the rest of the jigsaw intact while the search goes on for that last infuriating missing piece.
It may be that, sometime in the autumn, the Agreement's many supporters will sadly conclude that it cannot be saved, and will steel themselves to starting the whole thing over again. But that moment has not yet arrived. Perhaps a new attempt will be made right away, or more likely everyone will take a break and come back to it refreshed in the autumn.
In the meantime, there will be much analysis, some of it centring on just how seismic the republican initiative on decommissioning was, and whether it would really have delivered guns at some point. For the moment this will not be put to the test.
Most attention will, however, centre on David Trimble and on the balance of power within Unionism. He himself said last night that he had not attempted to sell Mr Blair's concessions to his party - which means there will be much debate on whether or not he personally would accept Sinn Fein in government, or whether he is open to having them, but on this occasion judged he could not sell to his party this particular deal.
There will be many who will claim that a bold act of leadership on his part might have won the day.
In the meantime, pro-Agreement elements will be hoping that the whole thing does not unravel over the summer and that a combination of marching season controversies, continuing political squabbling, and perhaps violence does not inflict lasting damage.
The peace process is by no means over. It has in the past absorbed all sorts of even harder blows, and has made a series of unexpected recoveries.
But it always seems to take longer than its supporters hope to deliver peace and a stable political settlement to underpin it, and once again there is delay rather than momentum.
Anger and Sorrow
"The vast majority of people in Ireland will be bitterly disappointed if we can't move forward. But we must at least make certain we do not move back."
Liberal Democrat leader
"There will be a lot of anger out there that after the all concessions offered to the Ulster Unionists by the Government to address their concerns, agreement could not be achieved on the creation of a fully functioning executive. One has to ask, what do people realistically expect to achieve with a suspension or a review? Do they think they will be able to deliver decommissioning soon if the agreement is suspended and the executive is not formed?"
Sean Farren, North Antrim Assemblyman
"The [US] President remains ready to intervene in any way. His message is the same for both the Unionists and the nationalists, that we have come too far in this process, there is too much at stake, to allow the issues that divide them to bring this process down."
Joe Lockhart, White House spokesman
"I will say to the presiding officer [when it comes to nominating ministers for the executive today] that he cannot get a cross-community executive and he cannot proceed. I will be the person with the hatchet to kill the beast."
The Rev Ian Paisley, Democratic Unionist Party leader
"Within republicanism there is deep, deep anger at the extent to which Mr Blair was prepared to subvert the Good Friday Agreement in an attempt to bribe David Trimble ... Trimble has quite clearly thrown it back in his face."
Mitchel McLaughlin, Sinn Fein chairmanReuse content