Once again the US Congress is being asked to increase military and economic aid for El Salvador. The administration would also like to increase the number of American military advisers there charged with trying to improve the performance of the Salvadorean Army. Lawmakers are properly concerned that the US military effort in El Salvador is not succeeding and that the only way out of the dilemma lies in a negotiated settlement.
Not only Democrats are worried. ''We need to find some framework for talks with the guerrillas,'' says Republican senator Nancy Kassebaum. ''We've always said a political solution is the only viable solution, but we're being pushed into a military solution.''
To the American people, too, the scenario in that tiny Central American country is uncomfortably reminiscent of Vietnam: Leftist guerrillas try to overthrow an authoritarian government. The US steps in to provide aid and advisers. The army begins to improve but still has not learned how to cope with guerrilla hit-and-run tactics. The guerrillas grow bolder. The US says the army needs more time and training - and American help.
Where does the cycle stop? It seems that the situation to be faced up to is that the war is stalemated. Some l8,000 Salvadorean soldiers are still unable to put down 4,000 guerrillas. Earlier this month 500 guerrillas carried out their boldest operation to date, briefly seizing Berlin, a town of 35,000 people. They were forced to retreat once the army arrived, but they scored a propaganda victory. Efforts continue to get the Salvadorean troops to use small, crack patrols instead of launching massive attacks, in the face of which the guerrillas simply fade into the countryside. But the Salvadorean military is said to be bitterly divided and lacking in leadership drive.
Meantime, it has come to light that during the guerrilla retreat from Berlin American advisers were on helicopters controlling the army operation; one of the Green Berets was hit by gunfire. There are rules barring US advisers from engaging in combat operations. The incident may be an isolated one, as the administration claims. But legislators cannot be blamed for drawing parallels to Vietnam.
Then there is the difficult issue of human rights. The administration has certified some progress, including a decline in the number of deaths by ''political violence'' and plans for a presidential election next year. Yet the record leaves much to be desired.
Despite these concerns, no one would suggest that Congress cut off American aid altogether. Certainly the United States wishes to continue pushing military, political, and economic reforms in El Salvador, however difficult it is to do so in the midst of a civil war. Yet it is a question whether additional aid - an extra $35 million - will appreciably alter the situation or simply pave the way for more and more increases. Holding the aid budget at its present level might keep the pressure on the Salvadorean government to make faster changes in military strategy and improve its handling of human rights questions.
More fundamentally, if the judgment of Congress is that the war is in effect at an impasse, the time has come to press for the nonmilitary solution that is Washington's nominal goal. Even some high-level voices within the US State Department are urging this course; Spain, Venezuela, and others have been approached as possible mediators. President Reagan remains opposed to negotiations before the guerrillas agree to lay down their arms, but the risk is that the longer negotiations are delayed the worse the situation might become for the government side.
It is hard to fault the advice of those who say the sides in the three-year-old civil war should be encouraged to sit down and talk.