Whatever else he may be, Ian Paisley is not stupid. So, when two weeks ago he proclaimed at a meeting filmed by the BBC that the IRA must be "humiliated", he could not have been in doubt about the fact that this statement would make it very difficult for that organisation to agree to the Government's proposal that photographs of decommissioning be taken, and later published, writes Garret FitzGerald.
As to whether it had been Paisley's intention all along to act in this way, or whether it was a late decision on his part, we cannot know. However, the two governments seem to have felt several weeks ago that he was at that stage prepared and even anxious to reach an agreement with Sinn Féin, so his provocation may have been more a reaction to problems within his party rather than a pre-planned move.
Given that some of Ian Paisley's DUP colleagues were either unenthusiastic about the proposed deal, or wished to see it postponed until after the expected UK general election next year, he may simply have come to feel that if, despite his public reference to "humiliation", the IRA nevertheless agreed to the photograph proposal, he could then have crowed over what he had publicly defined as their "humiliation" - and, if they refused the photographs, he could then blame them for the failure of the peace process.
Which is precisely what he has since done.
Up to the very end of the tortuous negotiation, Sinn Féin, although demurring at the photograph proposal, had nevertheless been careful in its talks with the two governments not to rule this idea out altogether.
This ambiguous Sinn Féin stance seems to have encouraged the two governments to include provision for such a measure in their final proposals.
The subsequent attempt by Sinn Féin/IRA to assert that they had all along rejected any photographic element thus carries little conviction and seems rather to be a cover for the IRA's negative reaction to Paisley's provocation.
Maybe, at some point in the future, this photograph issue, which is both literally and metaphorically "for the optics", can be fudged in some way. What cannot, however, under any circumstances be fudged is the omission from Thursday's IRA statement of the crucial first half of the two governments' required assurance: "Recognising the need to uphold and not to endanger anyone's personal rights and safety, all IRA volunteers have been given specific instructions not to engage in any activities that might endanger the new agreement."
The clear effect of this deliberate omission is that the IRA wants to retain for itself a right to decide which future actions by its "volunteers" (these apparently are not "going away") that endanger people's rights and safety would also endanger the agreement. We have had too much experience of the way Sinn Féin/IRA have in the past manipulated ambiguities to fall for this one.
As someone who has backed the peace process from its outset, despite qualms about many of the unpalatable compromises that this has entailed, I have to say that, in my view, unless this commitment is made unambiguously by the IRA, all bets must be off.
At this stage it is Sinn Féin which most needs early decommissioning so as to enable it to start extending the narrow foundation of political support that it has so far been able to secure in the face of its continued paramilitary involvement through the IRA.
The current Sinn Féin support base is effectively confined to two elements: traditional support in some Border areas and north Kerry, and some newly-won support in parts of cities with areas of disadvantage.
Public opinion polls have consistently shown that Sinn Féin's support is moreover concentrated within a quite small segment of the electorate: namely, among voters who are male, and young, and also working-class.
Thus twice as many men as women support Sinn Féin, and that party's support is also twice as high among the one-third of the electorate under 35 years as it is among the two-thirds who are older.
Finally, those classified for polling purposes as working-class are also twice as likely as middle-class and farmer voters to support Sinn Féin.
Clearly, among young working-class males, who constitute 8 per cent of the electorate, there are many who do not seem to share the sensitivity of other sections of the community to the past record of violence of the IRA, and this small group provides a quite disproportionate share of Sinn Féin's current support - so much so that the party cannot have much more to gain from within this limited category of voter.
The corollary of this is, of course, that Sinn Féin's support remains very low among the remaining 92 per cent of the population. This is where it badly needs to make progress.
In order to succeed in this it must reach out to older voters, to farmer and middle-class voters, and especially, I believe, to women voters - who are particularly negative about all forms of violence, including political violence.
The fact that opinion surveys have recently shown that 80 per cent of the total electorate - which must mean about 90 per cent of non-Sinn Féin voters - are opposed to the release of the Garda McCabe killers demonstrates the difficulty facing Sinn Féin in securing support from the vast bulk of the electorate so long as the IRA continues in existence, armed and refusing to abandon its claim to decide whose human rights and personal safety it may attack.
Arms decommissioning and the abandonment of this claim will not overnight eliminate negative attitudes among this vast majority of our electorate towards Sinn Féin.
That will take time, and we are already halfway through this Government's term of office. That is why, from Sinn Féin's point of view, there is urgency about decommissioning.
Sinn Féin is clearly anxious to secure a significant foothold in the next Dáil so as to enable it to achieve its first objective: being able to exert upon what they hope may be a future Fianna Fáil-led government the kind of influence that Labour and the PDs have exercised over such governments at different times during most of the past 15 years.