The decommissioning of the IRA's entire arsenal, following the formal statement in July that it was ceasing all other activities and committing itself exclusively to a peaceful democratic path, is a major historical landmark for the entire island, writes Martin Mansergh
For more than 80 years, since the war of independence, successive Irish governments have wanted the IRA to go away. Eamon de Valera, in the 1930s, worried about the guns still in their hands. In 1938, in a dreadful act of irresponsibility, surviving members of the Second Dáil, then no longer in Leinster House abdicated such political legitimacy as they possessed to the IRA.
From then on, at regular intervals, the IRA cut across national policy, endangering the survival of the State and its neutrality during the second World War and counteracting many attempts at rapprochement with the North.
In parts of the countryside and in deprived urban areas the IRA represented a shadowy force outside the law, one it was unwise to cross or provoke. The grounds of my family home in Tipperary, let when my father was young, was the scene of the murder in 1931 of Garda Supt Curtin, who had allegedly threatened some local volunteers with the law.
This led to the introduction of draconian legislation in the final months of the Cosgrave administration in 1931 and to a split in the Labour Party. A faded cross on the wall by the gate marks the spot. Close by, I have planted a beech tree, given to me five years ago by Gerry Adams, as a "Tree of Peace".
The total decommissioning of all IRA weapons was long vociferously demanded by, among others, the Rev Ian Paisley, who seems to find its fulfilment literally incredible. Of course, it was entirely predictable, not least to the republican movement, that even that radical step would never be enough.
Parnell - who, with much less reason, was equally distrusted and detested by British conservative opinion - explained patiently to Katharine O'Shea why her desire for him to clear himself of accusations (based partly on forged letters published in the Times in 1887) of association with crime could not be satisfied: "If Ireland wanted him to cudgel a clean bill of health out of England, she would find work for all the blackthorns she grew".
No one is going to cudgel a clean bill of health out of Dr Paisley for the IRA. It is best to let the new reality, in which the IRA has, in an astonishing reversal from 1938, handed back the baton to Sinn Féin, gradually sink in.
The best reason for believing Gen de Chastelain and the independent witnesses, Mr Good and Father Reid, apart from their integrity and experience, would be the disastrous political consequences for Sinn Féin of any organised, systematic or substantial deception.
Their enemies are waiting in the long grass to pounce, not just on them, but on everyone else who reacts in good faith to the IICD.
We do have certainty about the state of loyalist decommissioning. Apart from an LVF stunt some years ago, it stands at zilch.
One might think, given the violent attacks of recent weeks, that unionist leaders would be more preoccupied with the influence they now need to exercise. The establishment of peace, stability and democracy in Northern Ireland and community self-respect require the same cessation of all activities, including intimidation and extortion, from loyalist organisations and decommissioning of their weapons. The same goes for dissident republicans.
It has been a long road, requiring much patience and perseverance. In the past two years, growing impatience has also played its part. Bertie Ahern has devoted an enormous amount of time to mainly private persuasion, finally achieving a result which eluded all his predecessors. And the pragmatism of Tony Blair contrasts with what went before.
At official level, over a 12-year period or more, Tim Dalton, the now retired secretary-general of the Department of Justice, has been the key go-between with Sinn Féin on decommissioning, working with others in both the Taoiseach's office and Foreign Affairs, who never lost sight of the bottom line: securing and consolidating peace.
It is to the credit of Minister for Justice Michael McDowell that, despite differences in temperament, he continued to encourage that work until it was brought to a successful completion.
Gen de Chastelain, like senator George Mitchell, might easily have thrown in the towel. Both men have been rewarded for ignoring insults and prevarication.
Devolved government will take time to restore. One cannot expect people and parties who were made to wait so long to jump immediately the main obstacle has been removed.
Provided that the present course is confirmed and maintained, Sinn Féin will become eligible for participation in government North and South. In policy terms, as Dessie Ellis acknowledged on Tuesday's Prime Time, a lot has to be done to establish compatibility with other parties on the economy and on Europe and to move beyond being a party of protest.
In the South, no one has a right to be in government unless, on their own or with others, they can rely on a majority in the Dáil. The issue of confidence is paramount. Fianna Fáil will do nothing to jeopardise the confidence in the economy which has been built up over recent years, not even for the sake of staying in power.
Last Monday's announcement was a great advance, both nationally and internationally, an example to others caught up in hopeless and intractable conflicts and to those groups involved in terrorism as well as the states trying to counter them.
For once, satisfaction in an achievement, which has also required immense leadership from Adams and McGuinness, and clear thinking by IRA volunteers, can be shared both by the republican movement and the Irish people.