Five months after a costly, tragic war is none too soon to ensure that the Falkland Islands will not fall into a diplomatic limbo inviting new hostilities. Thus the current United Nations activity toward renewed negotiations between Argentina and Britain is welcome.
To be sure, Argentina was hardly the ideal party to initiate this activity in the form of a General Assembly resolution calling on the two countries to find a peaceful solution as soon as possible. Argentina's self-interest is obvious. The hollowness of its position is further indicated by its formally reserved option of further conflict. And, indeed, by its earlier defiance of a Security Council resolution it now brazenly cites in behalf of its own.
That April resolution, No. 502, demanded not only a cessation of hostilities but immediate withdrawal of all Argentinian forces - which did not happen until their total defeat by Britain. If the Argentinian invaders had complied, then the final part of 502 - calling on both parties to seek a diplomatic solution - could now be well under way. And how many lives might have been saved!
Britain understandably resists what it considers too quick a return to negotiations with such an adversary. Particularly on the basis of a General Assembly resolution that it finds unsatisfactory in several ways. At a minimum, Britain is right in criticizing the resolution for slighting self-determination as an issue in what is called a ''sovereignty dispute.''
There is a reference to ''reaffirming the need for the parties to take due account of the interests of the population.'' But even this was not there until Britain's ally, the United States, began seeking to moderate the text.
The document finally was acceptable to the US if not to Britain. The US's announcement that it would vote for it became part of a process of restoring relations with Latin American countries that had been alienated by US support of Britain in the war and that joined Argentina in sponsoring the resolution.
These countries must see that the Argentinian invasion and refusal to withdraw left the US no alternative but to side with Britain both as an ally and as a victim of the violation of international law. By the same token, now that the conflagration is over, they are justified in expecting the US to support the diplomatic approach it favored all along. Nor should Britain have any apprehension that a US vote for diplomacy is a vote against America's old friend.