Toward Irish accord

In the wake of the Brighton terrorist bombing, greater importance than ever is attached to next month's expected meeting between British Prime Minister Margaret Thatcher and Irish Prime Minister Garret FitzGerald.

One of the presumed purposes of the IRA bomb was to prevent useful dialogue over the future of Northern Ireland by angering Mrs. Thatcher's Conservative Party. This must not be permitted to happen. It is heartening to note the immediate response of Dr. FitzGerald that the terrorist incident would, on the contrary, ''reinforce the growing determination of the people of Great Britain and Ireland that we are in this together and that the will of the people ... will prevail and endure.''

Last Friday's bombing of the hotel of Mrs. Thatcher and other top Conservative Party officials illustrates the importance of removing the causes for dissension in Northern Ireland upon which violence can feed.

Fundamental differences of opinion, in addition to years of mutual suspicion, exist between the two sides in the Northern Ireland controversy. On the one hand are the predominantly Roman Catholic Republic of Ireland and its supporters in Northern Ireland, who seek a unified Ireland in some form. On the other are the majority Protestants of Northern Ireland, supported by Britain, who aim to retain affiliation with Britain.

A step toward further dialogue was taken last May with release of the New Ireland Forum report, formulated by representatives of Roman Catholic parties both of Northern Ireland and the Republic of Ireland, but excluding purveyors of violence. The report endorsed the concept of moving away from prejudices and toward Irish unity, but with the Protestant loyalists retaining some sense of Britishness. The document immediately encountered suspicion and hostility among loyalists, who saw it as an attempt to produce the united Ireland they oppose.

Long awaited has been an official response by the British government; officials of the Republic of Ireland have been saying they expected it at the November conference. Before this latest terrorism the Thatcher government already was in a difficult position, trying to figure out a way to move the process of accommodation forward a step without undercutting the position and legitimate concerns of the Ulster loyalists.

The Brighton bombing only makes more challenging the Thatcher posture. Her government does not want to be seen, at home or abroad, as bowing to the pressure of violence. Yet it is all the more important now that the conference be held and make measured progress - in spite of the violence, rather than because of it.

All responsible parties should continue to oppose such violence in the strongest terms and take stringent actions to prevent it. One necessary step is the strengthening of security precautions for the prime minister and other top British government officials, a process now going forward. In addition, efforts to clamp down on the smuggling of arms to IRA terrorists should continue.