Leading Article: George Mitchell is right to make no promises on Ireland

IS THIS the beginning of the end for the Northern Ireland peace process? We must hope that it is not. Were it to fail then, having exhausted the political process in the most optimistic phase in the life of the province for decades, the paramilitaries might well decide to abandon even the twin track of the "armalite in one hand and the ballot box in the other" and, to adapt a phrase, adopt exclusively violent means to achieve their goals. We might then witness violence of unprecedented ferocity.

So it is understandable that the return of Senator George Mitchell to Belfast has been greeted with so much hope. Even though he sensibly claims not to have a "magic wand", he has assumed a talismanic quality. No one has forgotten that it was only after two years of his careful brokerage that the Good Friday Agreement - which remains the best hope of peace for decades - was concluded. The Senator enjoys the respect and trust of all the parties. He has set no artificial deadline for the review.

But to recognise the qualities that Senator Mitchell brings to the province is also to acknowledge the failure of the other "honest brokers", and what a dangerous turn events have taken. The Secretary of State, Mo Mowlam, has long been regarded as "green tinged" by the Unionists, and attracted their open hostility, even contempt. The arrival of Mr Blair at Stormont once seemed to have near-mystical effects - until the failure of his and Irish Prime Minister Bertie Ahern's "blueprint" for peace in July. With that, most of the shine has even dulled on Jonathan Powell, the Prime Minister's Chief of Staff. Senator Mitchell is, so to speak, the last talisman in the locker.

It is unfortunate that Senator Mitchell's arrival will be so closely followed by the publication of the Patten review of the RUC later this week. This is a traditionally difficult area for Unionists and Republicans alike. Indeed, it was this very sensitivity that led to the review of policing being "farmed out" to Mr Patten's committee in the first place. If they are sensible, then the parties will not allow their real and understandable concerns to hold up the overall Mitchell review. Although the reform of the RUC is part of the Good Friday Agreement, it also well overdue in any case, as is, in a very different context, reform of the Metropolitan Police. It could proceed independently of political developments.

Far more hazardous is the issue of decommissioning of IRA weapons, again necessarily fudged in the Good Friday Agreement. But all political roads lead back here. The Senator has recognised the limits of his own abilities. He declares that "whether it is done is up to the political leaders". The best chairman in the world can't succeed where the participants want to fail. Clutching at a talisman, however charmed, will not be enough.