A conviction that can only help the peace process in Northern Ireland

The conviction of the leader of the Real IRA, Michael McKevitt, who has been sentenced to 20 years in prison, has rightly been described as historic. It is the first time that Ireland's post-Omagh anti-terrorist legislation has been used, and it was wielded by the authorities to spectacular effect.

Historic or not, the end of McKevitt's career is heartening news for the survivors and relatives of the victims of the Omagh bomb. Twenty-nine people and two unborn babies died in that atrocity, the worst of the Troubles, whose fifth anniversary falls next week. The aim of the so-called Real IRA at the time of the bombing was clear: to destabilise the peace process. It did not succeed in that, but the misery it caused to the lives of so many people persists. Many of the victims are engaged in a civil action against leading republican dissidents to try to secure some justice for their loved ones. The police investigation into the Omagh outrage continues.

However a longer-term impact of this blow to republican dissidents, and one that would be truly historic, may well lie in its effect on the peace process. While most of Northern Ireland's political leaders are enjoying their holidays, little progress may be expected before the autumn. But then the British and Irish governments will begin again the process of nudging them towards a renewal of the power-sharing and cross-border arrangements, and, in particular, towards preparing the ground for those much delayed elections to the Northern Ireland Assembly.

It may seem eccentric to view the incarceration of McKevitt, a pure act of natural justice, as a "confidence-building measure", yet that is precisely what it is. Unionists and nationalists alike will know that there is now that much less of a chance that they, their friends or their relatives will find themselves victims of sectarian violence. Their political leaders have the opportunity to use this small but important victory for the right ends.

Which leaves the precarious state of some of the parties themselves. There is a simple method of gauging the political health of each of the Northern Irish parties; the louder they call for fresh elections to the assembly, the better they expect to do. Thus it is that Sinn Fein is vocal in its demands for democracy to be restored rapidly, and David Trimble's Ulster Unionists seem content to insist on more movement on disarmament from the republicans before they are prepared to countenance the resumption of political business as usual.

A few weeks ago at a speech in London, Martin McGuinness, Sinn Fein's chief negotiator and the former minister of education in Northern Ireland, made a speech in which he, yet again, called on Tony Blair to press the Unionists to drop their demands. Mr McGuinness ought to understand better than most how difficult it is to pressure Unionists into doing anything. The threat to Mr Trimble from his own dissident MPs, Jeffrey Donaldson and David Burnside, is real.

The continued activities of the provisional IRA, embarrassingly highlighted by the current trials of suspected terrorists in Colombia, do not inspire Unionists to feel trust. Neither does the continued, if weaker, existence of the Real IRA and the Continuity IRA, both of which have been able to function intermittently during Mr McKevitt's absence in prison these past two years. Perhaps the revelation that Gerry Adams has been at real risk of assassination by republican dissidents will concentrate some minds in mainstream republican circles.