Yesterday we learned that the "how" of putting arms beyond use was established. Next on the agenda is the "when" and, with the usual caveats, there were some signs that there could be movement on that vital front soon.
A "hugely historical breakthrough" was how the Sinn Fein president, Mr Gerry Adams, described the statement from the Independent International Commission on Decommissioning (IICD). And indeed it was but there are many Doubting Thomases in the unionist camp, so expect much semantic analysis in the next couple of days.
Gen John de Chastelain after meeting an IRA representative learned the methodology of how the IRA could put its arms beyond use. The IRA representative described himself as "P. O'Neill", Dr Ian Paisley told us after his meeting yesterday with the general.
Whether or not this was a pseudonym, Gen de Chastelain was none the less sufficiently moved to write: "Based on our discussions with the IRA representative, we believe that this proposal initiates a process that will put IRA arms completely and verifiably beyond use."
We don't know when that would happen. And that was where unionists placed their spotlight yesterday. The Ulster Unionist Party leader, Mr David Trimble, expressed satisfaction with the "how" but he too wants to know "when".
He didn't close any doors however, accepting that the IRA initiative was "significant" but withholding a definitive response until the IRA delivers more substantively. One was struck by how calm and collected he was after his meeting with the Northern Secretary, Dr John Reid, yesterday afternoon.
It was significant that in his press conference he also focused on the SDLP and whether it would sign up to the policing proposals. He appeared to be signalling that should the IRA deliver on arms he would also require commitments that the SDLP would join the proposed Policing Board. Were this to happen he could argue that for the first time a significant portion of the nationalist population supported the policing arrangements for Northern Ireland, which in turn might allow Mr Trimble to persuade unionists to at least tolerate the difficult policing and other aspects of the British-Irish blueprint.
But those in the staunch No wing of unionism, when they had analysed the brief statement from the IICD, saw it as illusory and worthless. Such was the response from Dr Paisley and others.
Hardline UUP MP Mr Jeffrey Donaldson was also unimpressed. He referred to the decommissioning legislation. Arms must be "rendered permanently unusable and permanently unavailable", he said. "Actual decommissioning is our bottom line," he added. He wanted the evidence, and there were many more like him yesterday.
But was the Taoiseach, Mr Ahern, signalling that the IICD could be issuing another statement shortly that deals with that missing element?
One has to be careful in interpreting comments from Mr Ahern but none the less he appeared to be strongly hinting at forthcoming action. "It is a historic breakthrough," he told RTE. "Other things have to happen out of it, admittedly, but I'll be confident that that will happen."
Mr Ahern believed that the IICD statement was sufficient to allow the political process to continue. "And hopefully over the next number of days, perhaps the outstanding issue of the commencement of that process hopefully will also move on, and that will allow us to get on with the full implementation of the Good Friday agreement, which brings in all of the other issues of policing, demilitarisation and the stability of the institutions."
Mr Ahern at least appeared confident that this wasn't just manoeuvring by republicans or a cynical attempt to switch the emphasis from what the IRA will do next to whether the Ulster Unionists will accept the word of the general - to engage in the blame game, in other words.
It may also have been significant that the British government published a further "decommissioning scheme" yesterday, which gives the IICD, at its own request, more flexibility on how arms might be put beyond use. While the criteria remain that weapons are to be "permanently unusable and permanently unavailable" there is some shift in language from "decommissioning" to "putting arms beyond use", possibly in deference to the symbolic sensitivities of republicans who object to the D-word.
One neutral but informed insider posed a succinct question yesterday: "Is this move by the IRA a substitute for the IRA putting arms beyond use, or a prelude to the IRA putting weapons beyond use?" While the IICD was confident the IRA had initiated "a process that will put IRA arms completely and verifiably beyond use" could it take "10 years, 20 years, or 40 years" before that starts, he asked.
Answering his own question, he said the general and his colleagues on the commission had their credibility to maintain. Gen de Chastelain was hardly going to be a "dupe" or "patsy" to some sharp but meaningless wordplay from republicans.
Another source close to the centre of operations said it was implicit that for politics to work actual movement on arms must start relatively soon. "There are two effective deadlines," he said. "There is the 22nd of February next when the remit of the IICD runs out, and, perhaps more importantly, there is next Sunday, August 12th, when the British government could be forced to suspend the institutions or call fresh Assembly elections,".
What the IRA does next, and when it does it, will determine whether or not the British government must trigger some mechanism to suspend the institutions. It could do so for a day and then reactivate them to allow the Assembly and Executive to continue for another six weeks, which might be necessary to resolve outstanding matters.
But, if in the next day or so, the IRA made a move on decommissioning - putting concrete caps on two or three of its arms dumps, for example - then it just might be possible to call a special meeting of the Assembly by the weekend to re-elect Mr David Trimble and Mr Seamus Mallon as First and Deputy First Minister.
To quote one senior source: "If we can get the `when' question answered quickly, then I think what will be on the table from the IRA will be pretty irresistible, even for unionists."