"And I shall have some peace there, for peace comes dropping slow."
How right Yeats was: the peace process was quite extraordinarily slow. Twelve years have now elapsed since it was publicly launched, following several sets of encounters between John Hume and Gerry Adams, as well as some contacts between the Haughey and Reynolds governments and Sinn Féin. Even since the Belfast Agreement was signed, it has taken more than seven years to reach this point.
The origins of the process go even further back, to January 1983 when, having returned to government after a nine-month break, I reviewed the Northern Ireland situation at a meeting of the government's Northern Ireland Committee, which at that time comprised the taoiseach, ministers for foreign affairs and justice, attorney general, cabinet secretary and key Foreign Affairs officials.
The conclusion we reached was that the growing tolerance for the IRA in Northern Ireland following the hunger strikes - manifested in the strengthening of support for its Sinn Féin party - as well as the continued intransigence of unionist politicians and British governmental inaction were together posing an increasing threat to the security of the island, including that of our own State.
If Sinn Féin secured majority nationalist support in Northern Ireland while still engaged in violence, it might become emboldened to raise the level of violence in the North to civil war level, which could endanger the peace of the entire island.
The British government had to be persuaded to switch from its counter-productive hardline security policy towards one which would address the concerns of the nationalist minority in the North sufficiently dramatically to swing support back from Sinn Féin to the SDLP on a scale that would force a rethink by the IRA of its "Armalite and ballot box" strategy.
Although Margaret Thatcher might seem the least likely British politician to rethink British policy along such lines, if, perhaps with support from within her cabinet and civil service, we could secure such a British policy shift, the very fact that someone as hardline as she was believed to be had made such a move would hugely magnify the significance of this development.
To pave the way for such a successful Anglo-Irish negotiation it would, however, be important to secure all-party support within our State for a set of common principles which might be acceptable to the British government as an intellectual basis for such a new agreement.
And it would also be important that such a broad-based consensus would open up the possibility of acceptance by constitutional nationalist parties in the Republic of solutions that would fall well short of political reunification.
Because of the Fianna Fáil opposition's reticence about our government's agenda, the process of securing agreement to these two requirements for progress took twice as long as expected - a year rather than six months - but by May 1984 we had got what we needed.
The subsequent negotiation with Margaret Thatcher's government also took twice as long as we had hoped, but eventually yielded a result that persuaded one-third of Sinn Féin voters to switch back to the SDLP - partly, it has to be said, in reaction to the very negative unionist reaction to the agreement.
We now know that it was in the immediate aftermath of the agreement that Gerry Adams and Martin McGuinness - impressed by the scale of Margaret Thatcher's turnaround on the issue of minority rights and by her concession of a role for the Irish Government within Northern Ireland - decided, in Ed Moloney's words, on a "radical departure [ to] break the logjam" - viz. the "stalemate in the competition between the two nationalist parties . . . created . . . by the Anglo-Irish Agreement".
Seven years - during which I had almost given up hope of the kind of peace move by the IRA that the agreement had been designed to induce or provoke - were to elapse before, in the spring of 1993, John Hume was able to tell me privately of his success in persuading Adams to accept, de facto, the principle of consent by a Northern majority as a precondition to Irish political unity.
I have to add that from then on I never lost faith in the process coming eventually to a successful conclusion - basing my view on a simple calculation that, once they had launched themselves publicly on this path, there could be no way back for the two Sinn Féin/IRA leaders, McGuinness and Adams.
It must be said that the success of the peace process has been due to a combination of two elements: first, the skilful leadership with which thse two men led their IRA colleagues to abandon violence in favour of democratic action; and, second, the equally skilful diplomacy of successive Irish governments, including the present one, in their relationships both with Sinn Féin/IRA and with successive British governments, generally assisted by bipartisanship at home.
Historians will, I think, speak well of Irish diplomacy in relation to this issue across the decades.
They will also, I believe, admire the way in which both John Major and Tony Blair - the first two British prime ministers who were free from distorting personal memories of Irish neutrality during the second World War - successively played their hands during the 12 years since 1993.
There is, of course, more to be done to bring this complex and sensitive process to a successful conclusion.
First, the participation of Sinn Féin in Northern Ireland policing - no reference to which appears in the IRA statement - has to be sorted out, presumably through further Sinn Féin/British government discussions, the outcome of which has, hopefully, been largely predetermined.
Moreover, the arms must be decommissioned in a manner acceptable to unionist opinion. In this connection it has been noticeable during the past 10 days that both the chairman of the DUP, Maurice Morrow, at the MacGill Summer School, and Jeffrey Donaldson, on radio last Thursday, skilfully finessed questions about the photographing of decommissioning, an issue which created major problems last December.
No doubt in the months ahead Dr Ian Paisley will keep his followers happy with loud denunciations of Sinn Féin, but if, as we can expect to happen, the monitoring body is able to report in January that the IRA has, in fact as well as in word, abandoned violence and criminality, we can expect direct DUP/Sinn Féin talks to take place during the first half of next year and a new Northern Ireland executive to be in existence before the end of 2006.
For the DUP now has nowhere else to go. Its credibility, even with some of its own supporters, would evaporate if in these changed circumstances the party failed to join in a new power-sharing Northern Ireland government system during the course of next year.
Yes, it will have taken an unconscionable length of time for peace to drop on the North, and indeed on the whole of our island, but it has been worth the waiting.