IT SEEMS that at least one part of the American government, centered in the State Department, fears that the bottom may drop out of the current American policy in El Salvador: either the government's situation there will deteriorate or congressional support here will fall. This is, in our view, a correct, conservative and prudent analysis, given the Salvadoran government's continuing difficulties and the growing unrest in the American Congress. It is the basis for the consideration now being given to a new American approach to resolving the multiple issues--peace, security, power, justice, regional stability, external influence--of the war.

To judge by what is known, the State Department is dead set against cutting or conditioning the current life-sustaining American aid to El Salvador in order to compel Salvadorans either to do more in human rights and reforms or to enter negotiations with the left. There is some favor for this approach in Congress, but none in the Reagan administration. Rather, the department means to try, through an intermediary, to see if negotiations can be started between the two Salvadoran sides.

Explicitly, the effort rejects the guerrillas' proposal for talks in which the left would gain a share of power without having earned it in elections. But the effort also involves, implicitly, backing off the support the United States has so far given the Salvadoran government's plan to let the left compete in elections run by that government; the left, distrustful and no doubt hoping for more than it could earn in elections, has spurned the offer. Instead, the United States would support "the cooperative development of political processess that are democratic and that provide the security as well as the means for reconciliation." Just what this gobbledygook means only talks could tell.

But that is running ahead of the story. The first requirement is for the administration as a whole to decide whether it wishes to experiment with a new approach. Some important quarters are holding fast to the current policy. They are not frivolous. There need be no apology for a policy of supporting the Salvadoran government in battle, in reforms and in elections.

The question is how the policy is working, and the increasing evidence is that it is not working well enough: the war goes on at great cost and without apparent end, and what is built up by slow and irregular progress in reforms and rights is constantly eroded by violence arising at both ends of the political spectrum. This is the urgent reason to consider a policy that would conceivably isolate the extremes and allow the pursuit of peace.