Before retreating to the hills of northern El Salvador last week, leftist rebels attacking the El Paraiso Army base left the United States a potential political bombshell: Amid the rubble of the gutted garrison was the body of an American military adviser - the first to die in combat in the country's eight-year civil war. In Washington, however, there have been no political explosions.
The key reason, according to political observers, is relatively simple: The Reagan administration policy in El Salvador continues to draw broad congressional support, stemming from both the 1984 election of President Jos'e Napole'on Duarte and the perceived lack of alternatives.
``If this had happened in 1981 or '82, you would have seen a stream of resolutions asking for our advisers to withdraw from El Salvador,'' suggests a Democratic congressional aide. But because of the lengthy presence and low-key role of the 55 US advisers there, fears of another Vietnam-style escalation ``have been assuaged,'' he says.
Instead of provoking specific action, last week's attack only prodded a few nagging questions about the future of the war in El Salvador.
Experts offer a flurry of other explanations for the seeming lack of concern: Congressmen did not want to capitalize on a tragic event; they were overloaded last week with major bills; as El Salvador's political and economic conditions have deteriorated in recent months, they've been preoccupied by the contra controversy; and above all, they don't see options to giving support to the Duarte government.
At the same time, President Duarte's influence at home has waned - and not just because of stepped-up rebel activity. Duarte faces a growing threat from restless right-wing political groups supported by the private sector. And among the poor and powerless, tens of thousands of whom remain homeless six months after last fall's devastating earthquake, there is a strong current of disenchantment.
``There's a growing awareness in Congress that all's not well,'' explains Cynthia Arnson, a consultant to Rep. George Miller (D) of California. ``But to translate that into the political will or desire to do something is very difficult,'' Ms. Arnson says. ``The issues now are much more complex, subtle, and less receptive to correction by Congress.''
In the early 1980s, debate raged on the House and Senate floors over ways to promote democracy and human rights in El Salvador. But those issues seemed resolved with Duarte's election and the drop in political murders by right-wing death squads - from a staggering 800 a week in the early 1980s to about 10 a month in 1986.
(Human rights activists still find the situation unacceptable. They point out that more than 1,100 political prisoners - the highest number since 1980 - are now detained in Salvadorean jails, 90 percent without trial. And, they add, there has yet to be a single prosecution of a Salvadorean military officer for the thousands of political murders of the early '80s. But the improvement has been dramatic enough to quiet Congress.)
Now there's little room for debate. ``Even those who can see the Duarte government unraveling don't consider that cutting off aid is a good way to support El Salvador,'' says Holly Burkhalter of Americas Watch, a human rights group. ``Members of Congress are really strapped for options.''
Some members - faced with El Salvador's complex economic and social issues - concentrate on ``conditioning'' the US military and economic aid program. Since 1982, the US has poured almost $2.5 billion into the country of 5 five million people. In the current debate on the fiscal year 1988 foreign aid bill, a few liberal congressmen are trying to prevent US support for police aid, while prescribing funds for activities such as judicial reform and human rights investigations.
Did last week's attack affect the debate? ``Not a ripple,'' a lobbyist says.
``But this is the first year since 1984 that we've had serious discussions at the committee level on aid to El Salvador.... It could be that we are taking the tentative first steps back to dealing with El Salvador.''