Belfast — The recent summit between the British and Irish prime ministers has helped to thaw relationships between the two countries after the chill of the Falklands war.
Predictably, Unionist politicians representing the 1 million Protestants in Northern Ireland remain extremely suspicious. They believe such meetings are part of a British ''sellout'' of the province to the Republic of Ireland, but their reactions this time have been muted.
Their language smacks of familiar rhetoric rather than of outraged betrayal. In London and Dublin the talks were regarded as a welcome opportunity to discuss matters of mutual interest and concern, including Northern Ireland but not exclusively so.
The outcome of the meeting at Chequers, the country home of the British prime minister, produced no surprises. Both Margaret Thatcher and Garret FitzGerald, the Irish premier, appeared to have achieved their limited objectives of ending the difficulties that marred London-Dublin contacts since the last meeting in 1981. These were caused chiefly by the lack of support from the Irish for Britain in the Falklands crisis last year.
Charles Haughey, the Irish premier at the time, took a firmly neutralist line and played a leading role in trying to orchestrate opposition to British military involvement in the Falklands. Mrs. Thatcher was not impressed.
Even earlier Mr. Haughey had used the first Anglo-Irish summit of 1981 to suggest that agreement on ''a totality of relationships within these islands'' pointed to tacit British approval of ultimate Irish unity. Mrs. Thatcher, a woman not to be misquoted, remained icily aloof from such a suggestion.
This time the current Irish premier, Dr. FitzGerald, publicly complimented Mrs. Thatcher for the interest she had shown in his plea that she make the Northern Ireland question a more serious priority for her government.
Unofficial sources suggested Mrs. Thatcher spent much of the time listening as Dr. FitzGerald outlined the Dublin view of the continuing Ulster crisis, particularly the rise of provisional Sinn Fein - the political wing of the Irish Republican movement - which threatens the position of the mainly Roman Catholic Social Democratic and Labour Party (SDLP) in the north.
Mrs. Thatcher refused to commit herself on the outcome of the report by the New Ireland Forum, which is expected next spring. The forum, consisting of the major Dublin politicians and the SDLP, has been trying to work out an agreement on Irish unity by peaceful means. The Unionists and the moderate Alliance Party in Ulster have refused to take part, thereby condemning the forum to a partial view of the island's politics.
Both sides at Chequers seem to have used the forum's expected report as a convenient excuse to avoid making a definitive statement on the current Anglo-Irish position.
The communique from Chequers deliberately acknowledged the part Dublin can play in helping to improve relations. There was strong endorsement of the regular meetings of the Anglo-Irish governmental council which was set up in 1981 to enable senior civil servants and politicians to discuss joint problems.
But, happily for Unionists, there was no discussion of joint sovereignty, which would give Dublin some unspecified role in Northern Ireland's security measures.
In short, both sides seem to have agreed to resume relations as friendly neighbors and to regard Northern Ireland as a common, but differently perceived, problem.
The report of the New Ireland Forum will be another sharp test of joint friendship, with Britain unlikely to accept a Dublin-based concept of Irish unity.