The acid test of the carefully crafted time table announced at Downing Street yesterday is whether it will succeed in bringing the political parties in the North to the negotiating table. Producing it has involved some dramatic changes of position, notably by the British prime minister. But that was inherent in the tortuous and difficult business of dismantling the obstacles that has taken - incredibly - the best part of a year and a half to achieve.

Mr Major's difficulty was political, and by any yardstick the distance he has travelled in the last few weeks is extraordinary. He has not only had to turn traditional British government policy towards political violence in Ireland on its head, but also to downface the vociferous yahoos on his own backbenches. With or without the Canary Wharf bomb, the problem was unchanging: you can punish the IRA and Sinn Fein for the inhumanity of their bloody campaign for the last 25 years, or you can treat with them. Trying to combine both, as events have shown, is time consuming and wasteful, and rapidly becomes a macho exercise in which victory and defeat, not the attempt to settle differences, are the dominant issues.

It is an entirely different matter to demand undertakings for the future. Quite properly, this will be central at the start of the substantive talks. If the spectre of a resumption of killing hangs over efforts to find a settlement, it will act as a perpetual harking back to traditional attitudes among unionists as well. On the other hand, a clear and credible commitment to the Mitchell Principles by Sinn Fein is the best possible solvent of unionist gut hostility to sitting down with Mr Adams to negotiate.

Left to itself, Sinn Fein, which loses no opportunity of declaring its democratic credentials, ought to have no problem about this. Violence, and democracy. don't mix. But in Mr Martin McGuinness's seeming. equivocacy in his first reactions last night there may have been, more reluctance to second guess the IRA than genuine criticism of a proposal that meets Sinn Fein's requirements while standing every chance of keeping the other parties on board. Frustration at the time that has been lost must be tempered by an acknowledgment that combining both elements in one programme for action is the political equivalent of turning a circle into a square.

Skilful diplomacy, and patience on both sides of the Irish Sea, have succeeded finally. Dublin's proximity talks, which Sir Patrick Mayhew said would take place, if at all, at a later stage, now become the starting mechanism as "multilateral consultations". The unionists, who disliked the Bosnian parallel, now recognise the utility of the concept. Mr Taylor, for the Ulster Unionists, has also signalled that they will be prepared to work with an electoral format other than the one they proposed. The unprecedented sight of sandcastles beginning to slide yesterday as it appeared that most of the political parties are likely to accept the formula, is positive and optimistic.

It is only a beginning, not an end. But if the IRA recognise that their resumption of carnage on February 9th created a watershed for public opinion, strengthening the unity of people against violent methods, we may now hope that politics, at last, will play the role that awaits it.