The implications of General John de Chastelain's announcement last evening are instantly substantive and, in a more far-reaching way, profoundly symbolic.
Taking even one kilo of semtex or one Kalashnikov rifle out of circulation is a step in the right direction. But the general confirmed that "a quantity" of IRA weaponry has been put permanently and verifiably beyond use. Even if there were to be no such further gestures, it represents potentially a saving of lives.
But this goes far beyond the immediate. For Irish physical-force republicanism, a Rubicon has been crossed. The organisation which proclaimed itself entitled to take up arms against the legitimate governments of these islands, which claimed the authority to take human life in the name of the Irish people, has publicly divested itself of those arms.
It is unprecedented. Even in 1923 when Eamon de Valera gave his "dump arms" order it was anticipated that they would be brought back into use in time.
A historic milestone has been passed. It is an affirmation by the republican movement - in tangible terms - that it cannot operate in both the paramilitary and the parliamentary worlds. It displaces the ambiguity of the ceasefire and of wordplay with the certainty of action. Let credit go where credit is due. Mr Gerry Adams and his lieutenants have led their organisation where many insisted they never could. It has been a long, hard and dangerous road since the early days of the Hume-Adams dialogue.
Credit also to Mr David Trimble whose adroit tactics and political courage forced the republicans to confront the contradictions in their own position. Many factors combined to bring the IRA to this point; the urgings of so many throughout nationalist Ireland, the disclosure of republican links with the FARC organisation, the changed climate after September 11th, the persuasion of influential figures in the US. But can anyone believe that there would have been decommissioning without unionist pressure? It can only now be hoped that Mr Trimble's party will recognise the success of his strategy and that he will be re-confirmed as First Minister.
With IRA decommissioning, other important elements of the peace process can now be put in place. The political institutions will be restored. There will be demilitarisation by the British in republican areas. There will be pressure upon the Loyalist paramilitaries to restore their ceasefires and to match the IRA in putting arms permanently beyond use.
Other consequences will follow inexorably for the republican movement. As disarmament progresses, the structures and organisation of the IRA will become irrelevant and fade away. Republican strength will be exercised through the institutions established under the Belfast Agreement - including, in time, it must be hoped, the new police service.
Last evening's statement from the IRA declared that the move on weapons was intended to "save the peace process". It will do that, assuming that what has now been announced is the first step on an incremental pathway. It will also prove to be the most advantageous and pragmatic move the republicans have made since the announcement of their ceasefire.