THE atrocities of the conflict in Northern Ireland never cease to shock, even though they have been occurring for more than two decades. The calculation behind the violence, and the senselessness - in an otherwise civilised country - of the killing and maiming by both sides still horrify even minds that have been numbed by constant images of violence. Over the weekend, a particularly savage attack took place. Gunmen from the group calling itself Ulster Freedom Fighters entered a pub near Londonderry and opened fire with automatic weapons. They killed seven people and wounded 11 others. The attack tookto 24 the number of people killed in the past week and a half. There is nothing ordinary people outside Northern Ireland can do to influence events there, except perhaps to pray. The conflict has deep religious, social and economic roots, which make resolving the differences very hard indeed. The task is made close to impossible by the activities of the most callous, or insane, of terrorists on both sides. Yet there is hope, even if it arises only sporadically. British Prime Minister John Major and his Irish counterpart, Albert Reynolds, have come up with plan which involves their two countries working together for peace. There might even be a role for theIrish Republican Army in this search - if it renounces violence. The IRA predictably has rejected the Major-Reynolds plan but it has been received warmly by more moderate Catholics and Protestants. The continuing dialogue between Britain and Ireland offers the best single chance of peace. Because both governments have legitimacy in the eyes of their respective supporters in Northern Ireland, any proposals they produce would have credibility - and some prospect of being accepted.