Peter Robinson of the Democratic Unionist Party accurately described the murderers who took the life of a 25-year-old Roman Catholic police constable in Northern Ireland on Saturday as "a few neanderthals".

And Gerry Adams of Sinn Fein correctly characterised this foul act as “a futile attempt to destroy the progress that has been made”. Such crimes do nothing to advance the cause of Irish unity espoused by uncompromising Republican dissidents. Today the overwhelming majority have rejected bombs for ballot boxes and there is no going back.

After three decades in which 3600 people were killed, the Good Friday agreement created a fragile peace. Former enemies sunk their differences in the desire for peace and stability. Republican politicians took seats on the board of the new Police Service of Northern Ireland (PSNI) and encouraged nationalists to join the new force. This reinforced the sense of betrayal harnessed by dissident splinter groups. Saturday’s attack was the first since March 2009, when two soldiers and a police officer were shot dead within three days by the Real IRA and the Continuity IRA respectively. On that occasion too, it was a Roman Catholic policeman who was targeted. Far from challenging the peace, their actions provoked a heartening show of unity from both sides of the sectarian divide and from their leaders in rejecting violence.

It is particularly sickening that the terrorists chose for their latest attack the town of Omagh, where the Real IRA massacred 29 people in August 1998, the worst atrocity of the Troubles. It is not enough for the Republican community to condemn such events. It must also aid the PSNI in going after the killers. Meanwhile it is vital that Protestant loyalist groups do not allow themselves to be provoked by such actions, thereby risking Northern Ireland’s hard-won stability and its potential for economic development and the revival of tourism.

Clearly, Saturday’s murder was deliberately timed to coincide with the campaign for elections to the power-sharing assembly. All the available evidence suggests that those who continue to incite violence in Northern Ireland are a tiny minority, without the community, or indeed international support required to sustain a long-term campaign. Now that it is accountable to the people of Northern Ireland, the criminal justice system offers the right response to the paramilitaries.