The Taoiseach, Mr Ahern, is correct when he says that Sinn Fein, rather than First Minister, Mr David Trimble, has more room to manoeuvre in the gathering crisis over the decommissioning of paramilitary arms. In what has been widely interpreted as a placing of the onus for compromise upon the republicans, the Taoiseach stressed the "serious limitations" facing Mr Trimble vis-a-vis his own power base.
If anything, the Taoiseach may have understated the parlous conditions now emerging around Mr Trimble. Even his immediate and most loyal supporters within the Ulster Unionist Party are likely to desert him if he yields on his declaration that he will not move to establish a shadow executive until there is progress on decommissioning. If Mr Trimble were to yield it would almost certainly lead to a no-confidence motion which he would lose. In such circumstances he would be obliged to resign as First Minister - with consequences for the peace process which might be nothing less than fatal.
Whatever may be going on behind the scenes between Mr Martin McGuinness and General John de Chastelain, the public stance of Sinn Fein and its IRA associates is brutally uncompromising. Twice the IRA has declared that it will never decommission its weapons. Sinn Fein's position is simply that it is obliged to use its best influence to achieve decommissioning within two years.
It does not see itself obliged to achieve a starting date or a schedule for that process. It does not even see itself obliged to secure success in its endeavours. In the meantime, it expects all those aspects of the Belfast Agreement which are to its own advantage to be moved forward, in particular that it should be allowed to take its seats in the new executive.
Sinn Fein professes that all that is required is for Mr Trimble to face down the rejectionists within his own party, as Mr McGuinness put it on Tuesday. But it is not that simple. Mr Trimble secured a narrow win among the unionist community in the May referendum on the Agreement, supported by a letter from Mr Blair and assuring the electorate that paramilitary arms would be decommissioned before any new administration including Sinn Fein members would come into existence. It may be true that Mr Trimble effectively created these preconditions outside of the text of the Agreement proper. But the reality is that if he had not done so the referendum would have been lost.
Perhaps the Sinn Fein strategy is to bring Mr Trimble down. Perhaps they have calculated that if he can be broken, unionism will revert to its previous condition of absolute entrenchment, effectively leaving the political field to the combined nationalist parties in the Assembly. If so, they are engaged in high-risk gambling for if Mr Trimble were to be unmade, it is possible that the whole Agreement might unravel. Alternatively, it may be that Sinn Fein is genuinely unable to secure movement from the IRA on decommissioning its weapons. It has been suggested that Mr Gerry Adams's leadership of Sinn Fein might be in doubt if he tries to force the pace. If this is indeed the case, then it is clear that Sinn Fein's ability to deliver a lasting peace - even in the event of its participation in the executive - must be in question.
It may not take all that much to break the present impasse. Mr Trimble has been adroit in his use of language and is not looking for anything that could be construed as an IRA surrender. He is looking for believable evidence of intent - and so is the unionist community which he represents. Sinn Fein and the IRA to date have given absolutely nothing and have made no signs to indicate that they will give anything. Unless that changes the prospects are poor.