Back from the brink. Peter Mandelson, Gerry Adams and David Trimble have breathed new life into Northern Ireland's political process, and won a fighting chance for devolution.

It isn't currently fashionable to credit Mr Mandelson for very much and in truth, of course, the initiative which delivered Saturday's IRA statement was driven by the British Prime Minister, Mr Tony Blair, and the Taoiseach, Mr Ahern. So much so, indeed, as to give rise to speculation in press and political circles that the Secretary of State had been effectively sidelined.

It is true that the whole point of Mr Mandelson's appointment was said to be to relieve Mr Blair of the constant hands-on responsibility which had consumed so much of his time in his first two years in office. As soon as it became clear that Mr Blair's chief-of-staff, Mr Jonathan Powell, was embarked on another round of shuttle diplomacy, there were plenty willing to encourage the notion that Mr Mandelson was being bypassed.

New Labour's own fixation on personalities encourages this sort of thing. There had been reports early on of tensions between Mr Powell and Mr Mandelson. Also, it has to be said, the Secretary of State is not universally liked, his sometimes regal manner grating on Dublin sensitivities in particular.

Throw into the mix the collective nationalist demonisation of him which followed February's suspension of the Executive, coupled with the Prime Ministerial-led effort which promises to lift it on May 22nd, and it is easy to construct a theory which has Mr Mandelson going the way of Mo Mowlam.

Easy, but wrong. Nobody suggests the Taoiseach's leadership of the Irish effort made a bit-player of the Minister for Foreign Affairs, Mr Cowen. Moreover, if this plan works, Mr Mandelson can return to London with flags flying. The latest advance on the republican position - whether or not it proves enough for unionism - will inevitably be seen in London as vindication of Mr Mandelson's original suspension decision.

The Irish had railed against it - themselves bypassing Mr Mandelson, consciously and deliberately, to make their pitch to the Prime Minister. With Mr Blair's support, Mr Mandelson stood firm, did what he had promised Mr Trimble he would do, and took the subsequent flak.

Moreover he and his officials quickly (probably almost immediately) divined the potential in the IRA's statement of February 11th and the missing component in the final version - the reference to putting weapons beyond use - as key to any speedy restoration of the institutions of government.

After all the huffing and puffing about Britain's unilateral suspension, the IRA leadership has reinstated its February position and moved beyond it. Mr Mandelson will feel entitled to some of the credit for producing an advance on the republican position which is a good deal more tangible than the "seismic shift" with which the British tried to wipe Mr Trimble's eye last July.

But is it sufficiently seismic to persuade Mr Trimble's doubting Willies? The anti-agreement case against is easily constructed. This deal requires Mr Trimble to accept that the IRA is never going to decommission in the terms in which he has defined it.

There is nowhere yet any commitment to the actual destruction of weaponry; no promise to produce an inventory of all arms held; no indication of the percentage in dumps to be opened to inspection in relation to the total; no obvious sanction in the hands of the inspectors should they find weapons have been used; no suggestion as to how weapons in other dumps are to be deemed secure; and no cast-iron guarantee that they can never be used again.

Underlying all this is the fact that unionists and republicans do not have a common interpretation of what the peace process actually is or where it is headed. The IRA's support for the process is arguably conditional upon it proving itself transitional on the path to Irish unity. The putative concession to unionists on the RUC's "royal" title seems to amount to little more than a technicality on the face of the Bill re-creating the force as the Police Service of Northern Ireland.

If Mr Trimble does not have every jot and tittle of this hammered down, he might be well-advised to come clean with his party. Unionists will not take kindly to being told this is the fulfilment of their every decommissioning demand by another means. The direct linkage between guns and government, devolution and decommissioning, has finally been broken.

Some of his supporters certainly would prefer him to tell the rank and file the truth - that this is probably as good as it gets; that it is clearly good enough for Mr Blair to be going on with; and that, tables turned, unionism is now set to take the rap if the agreement falls.

Having moved so far from their original position, Mr Trimble's supporters can be expected to argue strongly that decommissioning's real purpose was to provide the benchmark by which to test the sincerity of the collective republican commitment to purely peaceful means.

Moreover, they will be buttressed by an already widespread independent view that acceptance that dumps should be open to independent ongoing inspection at all is - in republican minds - tantamount to actual decommissioning.

Thus Mr Trimble will presumably contend that the republican movement has crossed the crucial psychological barrier. He will make his pitch to the Ulster Unionist Council knowing that he has more to offer in real terms than when he invited them to take a leap of faith last November.

Certainly his position looks immediately stronger than on the day 43 per cent of his party backed the Rev Martin Smyth's leadership challenge. Back then, the UUP thought itself the sole occupant of the high moral ground.

On May 20th, they will have to make their judgment against a changed set of political realities and imperatives. Some of his leading opponents privately concede Mr Trimble stands a good chance of winning through. However, it would be unwise at this stage to predict he will do so by a sufficient margin to settle the issue finally or save his party from a formal split. That possibility cannot be ruled out.

Until now, one of David Trimble's greatest strengths has been the confused and confusing position of the Democratic Unionist Party - vowing undying opposition to the agreement, while permitting Mr Peter Robinson and Mr Nigel Dodds semi-detached membership of the power-sharing Executive.

In the wake of Saturday's developments, however, Mr Robinson has appeared to signal a wholesale review of the DUP's approach both to the Executive and the Assembly.

If that results in an overtly more oppositionist role for the DUP, it could increase the likelihood of some defections from Mr Trimble's Assembly party, and reopen the question of a radical realignment within unionism. Mr Trimble, then, is still in play, and looking in better shape than for many weeks past, but the fight for the soul of unionism is far from over.