It will not be as easy as some think to blame the DUP for a continuing impasse in the North, writes Frank Millar, London Editor.
Is the political honeymoon finally over for the Democratic Unionist Party? Will the Rev Ian Paisley and his colleagues soon find themselves arraigned before the court of international opinion, charged with endangering Northern Ireland's peace by rejecting the latest "best ever" offer from the Provisional republican movement?
Could the IRA's reported offer of greater verification of future decommissioning tip the DUP into power-sharing government with Sinn Féin just ahead of the British general election expected next spring? Or might London-Dublin attempts to hold reluctant Paisleyites responsible for any continuing political stalemate in the North instead backfire on Mr Ahern and Mr Tony Blair?
The two premiers are giving the DUP and Sinn Féin final proposals for the phased restoration of the Stormont Assembly and accompanying British and IRA "acts of completion" permitting the appointment of a new power-sharing administration by next February. The Taoiseach has declared November 25th the deadline for acceptance or, at any rate, compliance by the two parties which achieved dominance in the Assembly elections a year ago.
Before giving them an opportunity to read the fine print, however, Mr Ahern has also signalled his suspicion that it is the Democratic Unionists who may be found wanting.
Having engaged with the new majority unionist party with all his customary enthusiasm, it seems Mr Ahern now entertains the fear, lightly dismissed by some officials over the past year, that the DUP leadership is prepared to talk the talk but with no intention of walking the walk before it completes the marginalisation of the rival Ulster Unionist Party come the general election.
Obviously both governments hope this fear will prove unfounded, and they can marshal formidable arguments as to why it is unnecessary for the DUP to delay concluding what some senior figures around Dr Paisley will privately concede is an inevitable political accommodation with Sinn Féin.
However, should the latest initiative fail, this is the essential context in which the current version of the blame game has been prepared.
The Taoiseach talks of the political process moving ahead in any event, of ratcheting up the pressure on the DUP, perhaps by strengthening the London-Dublin axis.
Last week our Northern Editor, Gerry Moriarty, suggested Mr Ahern was acting with Mr Blair's full knowledge and support, and there are good reasons for thinking it must be so. Mr Blair himself showed every inclination to blame the DUP for failure as far back as the Leeds Castle talks in September, his impatience all too evident at the DUP's failure to grasp an apparent IRA offer which he described as "remarkable in its substance and historic in its meaning".
It seems pretty clear that Mr Blair's disposition is rooted, in part at least, in a sense of guilt about the fate of Mr David Trimble and the Ulster Unionists following the Prime Minister's decision last October to allow the Assembly election to proceed, having twice postponed it because he saw no point in an election which did not guarantee a return to partnership government.
Despite the UUP leader's final failed negotiation with the Sinn Féin president, Mr Gerry Adams, Mr Blair trusted Mr Trimble to defy all the odds and somehow keep the show on the road.
When the unionist electorate availed of the opportunity to back the "alternative agreement" party instead, Mr Blair in turn attempted to blame the republicans for the erosion of the unionist centre ground.
The Prime Minister also apparently determined one other thing: that he would not be complicit in the final eclipse of the UUP by permitting the DUP to talk that talk all the way to the general election in which it might be accomplished.
Hence Mr Blair's original "deadline" of April, which became May, then June, then September, then the first fortnight in October and which is now, according to the Taoiseach, the last week in November.
However, Mr Blair appeared well ahead of himself at Leeds Castle, and as the latest deadline hovers into view some anxiety remains that he learned nothing from the mistake made there.
A massive "spin" operation, aided by the SDLP, certainly sent forth the message that republicans had offered to do great things by Christmas. The DUP was set up to take the blame then, too, yet the spin operation fell apart when Dr Paisley delivered the vintage lines: "We'll believe it when we see it. I'm too old to be bluffed."
In just two sentences the DUP leader confirmed he had seen nothing on paper, had been given no detail, no hint of schedules or timetables, much less the language with which the IRA might declare itself no longer in business as a paramilitary force.
This lack of clarity and certainty prompted the suspicion, subsequently voiced on this page, that Mr Blair and Mr Ahern had conducted the negotiation as if they were still dealing with Mr Trimble, whose willingness to tolerate degrees of creative ambiguity could actually be explained by his fidelity to the Belfast Agreement.
Perhaps Mr Blair's aides have filled in the missing detail in the intervening months, and history will be made by tea-time tonight. However, having won that particular argument with Mr Trimble, Mr Adams has signalled he will not permit the DUP to reinstate IRA decommissioning as a precondition for Sinn Féin's entry into government.
Whereas a year ago the failure to devolve policing powers to Stormont was portrayed as a "deal-breaker" from the republican perspective, senior DUP sources say they do not contemplate such a development within the lifetime of the present Assembly.
Moreover, Sinn Féin will surely contend it is in the nature of this process that "nothing is agreed until everything is agreed". Republicans don't traditionally "do" unilateral.
If the detail is there, the DUP might today find itself facing an offer it cannot refuse. But if it is not the DUP leader knows he need fear no blame where it matters to him - among the unionist electorate - for holding back and hanging tough.