There can be no reasonable doubt that the republican movement as a whole is the cause of the current crisis. Whether that is caused by internal dissent, misplaced expectations about its bargaining power, psychological reluctance to oblige a deadline set by David Trimble to satisfy his party colleagues, or some wishful thinking, is not something the rest of us can know definitely.
What is clear is that republicans have less than a week to decide whether they wish to save from disaster the process they initiated.
The Ulster Unionist Party has fulfilled all its obligations under the Good Friday agreement and has a very reasonable case that there should be a credible start to decommissioning. The UK government has delivered, or started to deliver, on all its obligations under the agreement, save two.
One of these, demilitarisation, has begun, but obviously awaits movement on decommissioning. The other, the Criminal Justice Review, was promised by Peter Mandelson in the House of Commons on Thursday "within weeks".
Only the loyalist and republican movements have failed to begin their duties.
Republicans gave unionists reasonable grounds to understand that there would be rapid movement on decommissioning. Apart from the appointment of an interlocutor, that has not been forthcoming so far. So republicans are ethically and politically in the wrong and isolated.
But all this does not mean that Sinn Fein has technically violated the Good Friday agreement, yet, and neither has the PUP, yet. All parties to the agreement have an obligation to ensure that decommissioning is completed by May 22nd.
The Assembly parties are free to determine by cross-community consent that Sinn Fein and the PUP have violated the Good Friday agreement if they resolve that they have been failing to use their best endeavours to initiate and complete decommissioning, and they can do that now, or they can do it on or after May 22nd.
The SDLP, and many others, are not likely to draw a definitive conclusion before then, so the Assembly is not likely to determine definitively that Sinn Fein and the PUP are in breach of their obligations until that time. So the question is: should a definitive verdict on Sinn Fein's (and the PUP's) obligations be left until then?
The UK government, with the apparent assent of the Government, has decided that the answer is "no, matters must be brought to a head now". Suspensory powers are to be obtained by the Westminster Parliament by next Friday; and the supposition is that they will be used, if necessary.
However, once the power of suspension is adopted by the Westminster Parliament a constitutionally decisive action will have been taken that is against the letter and spirit of the Good Friday agreement - even if it is adopted for the best of motives, and even if it has been provoked by republican (and loyalist) intransigence and collective cognitive failure.
The Good Friday agreement contains no provision for the Secretary of State to have the power of suspension. The Northern Ireland parties, in consultation over the implementation of the Good Friday agreement, embedded in the Northern Ireland Act 1998, explicitly denied the Secretary of State the general right to dissolve the Assembly and gave that power to themselves - which is why the Secretary of State is bringing forward fresh legislation to suspend it.
I submit that anything that alters the agreement, especially its institutions, without the consent of the parties that negotiated the agreement and the institutions established under it, is a breach of the spirit and letter of the agreement.
Why does this matter? In effect the Good Friday agreement made Northern Ireland into a "federacy" - a self-governing unit whose constitution could not be unilaterally altered by the Westminster Parliament without the consent of the devolved Assembly.
For the UK Parliament to assume the right of suspension would be consistent with the agreement only if it were to be supported by the Assembly through cross-community consent procedures.
This understanding of the Good Friday agreement is not shared by all. Plainly, some unionists rest their case for suspension upon a Diceyian reading of the UK constitution - in which the Westminster Parliament is entitled to do what it likes, irrespective of previous commitments, and irrespective of international treaties.
They believe that Westminster's sovereignty remains absolute, and that the repeal of section 75 of the Government of Ireland Act was mere "window dressing".
I believe, by contrast, that the British-Irish Agreement, which ratified the Good Friday agreement, is an international treaty which respects the right of the people of Ireland, North and South, to self-determination.
The Irish people, North and South, did not vote to endorse the agreement to give Westminster's parliament unalloyed sovereignty over Northern Ireland. They voted to endorse Westminster's sovereignty subject to the consent of the people of Ireland, North and South, and, in the case of the North, subject to the consent of their duly legitimate institutions, and subject to Westminster upholding the Good Friday agreement. That is why Section 75 of the Government of Ireland Act was repealed in the negotiations, and why the Irish people, North and South, were given to believe that the two governments would uphold the agreement.
While entirely sympathising with Mr Trimble's current plight, I believe it is wrong to justify suspension on the grounds that if he resigns he could not in future be re-elected as First Minister, given the balance of forces within unionism in the Assembly. True, the First Minister and Deputy First Minister have to be elected by the parallel consent procedure, and at present Mr Trimble would fall at least one vote short of the necessary total within the unionist bloc.
However, within the letter and procedures of the 1998 Act, agreed by the parties as the UK enactment of the Good Friday agreement, the Assembly can propose, by weighted majority, any intra vires amendment to the procedure for electing the First and Deputy First Minister, which could then be sent to Westminster for ratification.
In short, the suspension of the Assembly should not be justified on the grounds that that is the only way Mr Trimble can return to office. That is not true - there are "within agreement" mechanisms for accomplishing that desirable goal should Mr Trimble, unfortunately, feel obligated to resign.
None of these arguments is intended to excuse republicans. They are to blame for the current crisis, as are loyalists. Their actions, and inactions, are likely to lead to the first break in the formal rules of the agreement.
Republicans should be given no constitutional excuse for delaying on their obligations - and if they want to avoid the dangerous precedent of a suspension they know what needs to be done, and done quickly. If they say that that would be to act involuntarily, or under a threat, then the response of constitutionalists has to be that the IRA has been threatening everyone else by not declaring an intent to decommission.
With or without suspension, if republicans do not deliver on decommissioning on schedule by May 22nd, Sinn Fein should be declared unfit for office by the other Assembly parties, including the SDLP - as should the PUP (though in its case the verdict would have no sting since it is not entitled to ministers).
Constitutional politics are difficult. They should, wherever possible, be followed. A premature suspension would be a potentially fatal blow to Northern Ireland's novel and excellent constitution. But these constitutional thoughts prompt "realist" questions.
What rational republican can sensibly believe they have anything to gain from letting this crisis deepen? Republicans are not likely to be beneficiaries of institutional anarchy. They will be excluded temporarily from government in the North, and lose the otherwise strong likelihood of being in government North and South within a few years.
A centrist rather than an inclusive coalition government will replace the existing Executive if there is a restoration of devolved government. Any return to violence on the part of the IRA will see the rounding up of released prisoners and the co-ordinated repression of a movement which has been largely inactive for five years, and will therefore be a sitting target.
In short, the IRA is ceasing to be a very credible military threat. Any hardheaded realist within republican ranks must know that the reforms and political opportunities promised by the agreement are much less likely to be delivered under direct rule, and certainly less likely with the IRA still in the field and with the "yes unionists" politically shipwrecked.
Any realistic defenders of the Northern nationalist community must know that now is the time to start decommissioning, en route to disbanding the IRA: the IRA has to be traded for the benefits of the Good Friday agreement.
That is the logic of the Good Friday agreement - it is time for republicanism's slowest learners to digest that fact.
Brendan O'Leary is professor of political science at the London School of Economics