LEADING ARTICLE: Justice from the barrel of a gun

There is supposed to be a paramilitary ceasefire in Northern Ireland. Yet the killing rate is approaching the level it reached during the quieter periods of the Troubles. Four men have been murdered this month. The latest victim, Martin McCrory, was shot dead on Wednesday night. The IRA seems to be responsible.

In short, the cessation of political violence no longer means a total ban on killings by the IRA, just as it never entailed an end to punishment beatings. The IRA is sending out a clear message: it will not wither away.

That is the uncompromising missive to George Mitchell, the US Senator appointed by Bill Clinton to head an international body looking into what to do about Northern Ireland's stockpiles of illegal weapons. It is probably no coincidence that the shootings began just as Senator Mitchell took up his post.

The IRA has an additional motive for these killings: to retain control over neighbourhoods from which it draws the core of its support. It has singled out the scourge of the community - drug dealers and criminals - for crude justice. Few local people will grieve for them. And there are not many brave enough to argue with an organisation that executes a small-time criminal such as Mr McCrory in front of his three-year-old son.

All of this is terribly depressing. These vigilante killings make it politically even harder for the Government to relax its insistence that at least some weapons should be decommissioned before Sinn Fein can join constitutional talks. So the danger of another stalemate in the peace process looms large.

The shootings should also dispel belief that the IRA will somehow melt away, its weapons left to rust like the guns of previous rebellions. It aims to remain a disciplined, vicious organisation, unwilling to forfeit its domination of certain communities.

There is, however, some hope. Sixteen months after the ceasefire, the IRA is still faithful to the cessation of political violence. There is no immediate sign that it is prepared to breach that aspect of the ceasefire. The popularity of general peace across Northern Ireland is such that few republicans want a return to 25 years of terrorism.

The only chance for challenging vigilantism and the shadow that the IRA still casts over Northern Ireland requires a long-term strategy, building on the political peace. It demands the creation of a settlement that is genuinely inclusive, claiming the allegiance of all communities, including Sinn Fein. Only such a state can, for example, produce a police force that the nationalist ghettos will back against the IRA. In time, the police should aim to be so supported by the population that, like their counterparts in the south of Ireland after the Civil War in the Twenties, they feel able to disarm themselves.

The Government, keen to keep the peace process alive, seems to be overlooking this month's killings. London, unlike Dublin, has not pointed the finger of blame at the IRA. But this month's killings should bring home to John Major the urgency of seeking a new constitutional agreement. He must press ahead with all-party talks, even if that means circumventing his precondition that arms should first be decommissioned. The present peace, secured without a political settlement - leading to vigilante law and a still strong IRA - is no long-term solution in a liberal democratic age.