IT IS A MEASURE of London's frustration in Northern Ireland that the British press now suggests that President Carter is about to unlimber an Ulster "initiative" aimed at providing jobs or, alternatively, producing a whole settlement. As far as we can determine, the administration contemplates no such departure. It is apparently mulling whether to confirm formally the Carey-Kennedy-Moyniban-O'Neill St. Patrick's Day appeal for an end to private American support fo the gunmen. That would be a well-meaning gesture, although no one familiar with the dark history of violence in Ulster can be sanguine about the effect of gestures, especially the gestures of outsiders. In any event, it would be a far cry from a full-bodies Carter "initiative."

The question, however, is not frivolous. Should the U.S. government start taking more of a direct hand in peacemaking in Ulster? It would not be surprising, at a time of rising ethnic interest in American foreign policy, if Irish Americans were to ask their government to heed the plight of their ancestral homeland and their kin. They have the requisite numbers (15 million), sophistication of national leadership and anguish. That by and large they have not asked suggests that they have as well a proper respect for the difficulty of cutting through the centuries of history that have produced Northern Ireland's crisis of communal relations, and of sorting out at transatlantic range the furies dividing the Protestant majority and the Catholic minority there. Irish Americans also seem to understand that, Northern Ireland being British, the problem is, first of all, Britian's. The general reluctance to poach is only heightened by awareness that, whatever their historical errors, the British in recent years have applied themselves just about as conscientiously as the circumstances permit.

In the campaign last year, it seems, Jimmy Carter stuck a "Get England Out of Ireland" button on his coat and paraded down Fifth Avenue. He was not doing well in the cities at the time. Since than, we trust, he has learned that the slogan he wore is the front for an unthinkable terrorist strategy: If the British pulled out, the IRA would attack the Protestants in order to provoke intervention by Ireland. Offhand, we can think of no campaign phrase worthier of repudiation on sober second thought. The United States cannot get itself into the position of negotiating even directly with contending guerrillas in a foreign country. It can do no less, and no more, than support whatever peacemaking initiatives the embattled people of Ulster mount for themselves.