The concept is so striking that it will take a long time to sink in. It is early days in the process, but the lack of outcry from the republican community is a clear indication that the offer has been grasped by the grass roots.
The republican movement has changed dramatically in the past two decades. Once it was very tightly controlled by the army council of the IRA, people who assumed titles such as quarter-master general, chief of staff, head of northern command and so on.
Now the movement is a much broader and more diffuse entity. It has well over a hundred thousand regular voters, it has MPs, assembly members and councillors, it has leaders who travel all over the world, who know the likes of Tony Blair and Bill Clinton well.
The IRA is still there: Gerry Adams said a few years ago that "they haven't gone away, you know". But Sinn Fein is now the powerhouse of the movement, the part of it that gets results.
The republican community is hugely proud of Sinn Fein, regarding Gerry Adams and its other leaders as tremendous ambassadors for their cause. Adams goes to Washington, to Dublin, to Downing Street; he's on Newsnight, he's on CNN; a thicket of microphones appears for him wherever he goes.
There is much republican faith in Adams, and by extension in his projection that this is the way to do business: by talking, by negotiating and by politicking. What the gun has is negative power; republicans now feel strong enough to do without it.
Within republicanism opponents of the peace process seem hopelessly old- fashioned, and no realistic alternative to the excitements and achievements of the peace process is offered. When splinters such as the "Real IRA" emerge look what happens: the Omagh bomb.
The process has delivered a lot for republicans, but in many ways it is still in its early stages. The IRA's guns have largely, but not completely, fallen silent: there are still occasional killings of which it is suspected, and its "punishment" attacks go on.
Even the optimists had thought the most they could hope for was a small element of decommissioning in a year or two, because of the political uncertainties that abound.
Since a government has yet to be formed no one is sure how its members will work together; a report on policing reform is being worked on but has yet to be published; and there is still a lot of loyalist violence out there. One widespread assumption was that the IRA would watch and wait to see how all this panned out; another was that even if things went well, any decommissioning would probably come as a token.
Few, if any, expected the proposition now put forward: Gerry Adams has repeatedly spoken of taking all the guns out of Irish politics but most thought this was a pretty meaningless mantra.
In the short term, the move has wrong-footed Unionist politicians and left them gasping, and there is no guarantee that a deal will prove immediately possible with this offer as its centrepiece. But this offer will have a profound and transforming effect since the idea of complete disarmament, once raised, will never disappear.
It will work away through the political psychology of every side, as a Holy Grail that has suddenly ceased to be mythical and become achievable.
London and Dublin clearly believe they can bring in enough safeguards to ensure that republicans keep to their word and give it all up. Unionism is going to take a lot more convincing before it summons up the nerve to jump too.
But this is an idea whose time has come, and it offers such a priceless prize that eventually it will work. At the beginning of this decade the emergence of "peace" as a possibility changed the whole course of politics. "Disarmament", too, is sooner or later bound to prevail.Reuse content