The dictionary probably doesn't have a word to describe the stupefied reaction there would be if P O'Neill did not respond positively to Mr Gerry Adams and Mr Martin McGuinness.
We had the same choreography when the IRA restored its cessation in 1997: first the call to the IRA from Sinn FΘin, then later the IRA announcing it was back in ceasefire.
It was a long, long time coming but in the end it didn't seem so painful, although for most republicans it is a daunting Rubicon to cross.
Yet, all it took was a single sentence in a six-page script from the Sinn FΘin president.
"Martin McGuinness and I have also held discussions with the IRA and we have put to the IRA the view that if it could make a groundbreaking move on the arms issue that this could save the peace process from collapse and transform the situation," said Mr Adams.
Sources say the IRA answer would come "quickly", possibly today, which should be in time to restore the Executive and institutions of the agreement to full working order before Thursday's deadline when Northern Secretary Dr John Reid would be forced to suspend them.
Mr Adams's use of the word "ground-breaking" suggests it will be a significant gesture, although one must remember that Sinn FΘiners and Ulster Unionists have different views of what constitutes "significant".
As well as a battery of reporters and photographers there were about 100 republican activists - almost a mini-convention - in Conway Mill in west Belfast when Mr Adams delivered what appears to have been a genuinely, if one will excuse the hackneyed phrase, historic speech.
The atmosphere throughout was quite charged, expectant and a little nervous. The republicans accorded Mr Adams a standing ovation when he entered the conference room. They remained seated when he finished his speech but virtually everybody in the room warmly applauded him, apart from one or two.
Apparent republican acceptance of the inevitable was hardly surprising because while Mr Adams wants "ground-breaking" action on arms from the IRA he and his fellow republicans had already broken the ground in advance for such a move.
The spadework began in May last year when the IRA pledged that in the right context it would completely and verifiably put its weapons beyond use.
It continued right through to early August this year when the IRA said it had agreed the "how" but not the "when" of decommissioning with Gen John de Chastelain's decommissioning body. Now comes the "when".
Mr Adams has complained of media hype and speculation about decommissioning, but that too suited his purpose because it was another part of preparing the troops for what comes next.
Mr Adams made it sound easy but he was particularly mindful of how he must keep grassroots republicanism sweet.
"It is a time for clear heads and brave hearts," he advised them. He went out of his way to appeal to republicans to "think strategically", "to stay united", "to stay together in comradeship".
His caution and concern were understandable, because here was the great icon of modern provisional republicanism urging the IRA to do what many republicans have insisted could never and would never happen.
But, while putting arms beyond use is contrary to republican dogma, was it such a risk?
Is it not the case that Mr Adams and Mr McGuinness are in such powerful control of the broad republican movement that with almost political infallibility they can rewrite the republican book of theology when they so choose?
"Think strategically," said Mr Adams.
It seems that after the slaughter at the World Trade Centre and the Colombia business, that's precisely what Mr Adams was doing.
This is the strategic time to start blowing up some Semtex or destroying a few hundred Kalashnikovs.
There is nothing more to be gained politically from prolonging the agony.
The Northern Secretary, Dr John Reid, played his part in the tick-tacking. He said that the British government would not be begrudging or ungenerous in its response.
The Minister for Foreign Affairs, Mr Cowen, said now was the time to "recapture the vision of hope and generosity represented by Good Friday 1998". Indeed.
If the IRA move is substantive then obviously the next crucial response is from Ulster Unionism.
Here too pro-agreement unionists must think strategically, and signs are that is what they are doing.
A dog in the manger response would allow republicans off the hook and again cast unionists as the wreckers.
Mr David Trimble is keeping his counsel for the moment but he will be happy.
His former arts minister, Mr Michael McGimpsey, said the Adams statement was "constructive and promising".
So there is real hope this time. The Rev Ian Paisley spoke of "dirty deals" yesterday but Mr Trimble will tell him that had unionists followed the DUP, Northern Ireland would never have reached this day.