When the Reagan administration looks at tormented El Salvador it sees a friendly "centrist" civilian/military government, headed by a Christian Democrat, Napoleon Duarte. It also sees a classic case of indirect "aggression" by international communism -- a ragtag guerrilla movement, heavily dependent on arms supplied by Cuba and other Soviet surrogates. Part of the cure, then, is heavy doses of economic and military aid, coupled with pressure on the government to ease up on repression and pave the way for free elections. But the key to long-lasting relief is seen in a surgical military effort to search out the opposition military forces and destroy them once and for all.

That's one diagnosis -- and one prescription.

For a second opinion, let me introduce Alberto Arene, a 26-year-old El Salvadoran exile and former member of the Christian Democratic Party who was working for the government on agrarian reform as recently as January of last year. He quit his job and slipped out of the country when confronted with persuasive evidence (a taxicab with three armed men parked in front of his apartment) that his name had very likely been added to the lengthening hit list of the government security forces' "death squads."

A professional economist with a master's degree from a Belgian university, he has since been working, first as a World Bank consultant and more recently as a traveling salesman and fund-raiser for the opposition Popular Front. Here in Washington, he has lobbied Congress for his cause. He has toured Western European capitals to drum up support from Christian and Social Democratic party leaders. He reports encountering widespread sympathy, and expects more of the same at his next destination, Mexico.

I cannot vouch for everything he says. But he looks -- in a double-breasted dark blue blazer, white shirt and regimental striped tie -- rather more like a rising young banker then, say, Che Guevara. I would safely count him as representative of a highly significant slice of Salvadoran society (Christian Democrats and non-communist leftists) whose disaffection and disillusionment constitute a monumental barrier to the success of current U.S. policy for El Salvador.

When Arene looks at his native land, he sees a harshly repressive right-wing military government, under the tight thumb of a rich and ruthless oligarchy, with only the thin facade of Christian Democracy in Duarte's presence as its nominal leader. "When the American administration speaks of a moderate government of the center," he says bitterly, "it is playing with words."

He sees the guerrilla forces as the home-honed military cutting edge of a political opposition movement whose representation -- peasant organizations, labor unions, the clergy, businessmen, technocrats -- reflects a wider consensus and a tighter cohesion than that of any comparable movement in Latin America.

Arene does not pretend the movement does not have Marxist elements or support from the communist bloc. But he says the rebels obtain most of their imported weapons (largely of Western manufacture) in the international arms market, using funds raised from sympathetic Christian Democrats and Social Democrats in Europe and Latin America -- and from kidnappings for ransom of prominent oligarchists.

The arms from outside are shipped through Guatemala and Honduras as well as Nicaragua -- and by sea. "If you try to control all the possibilities, even by very sophisticated means, you just can't do it," he maintains. And, in any event, he says most of the rebel arms are taken from government security forces.

Can the guerrilla "popular forces" be put down by overwhelming numbers of government troops. U.S.-trained and equipped with helicopters and other sophisticated gear? Not permanently, he replies with confidence. Repression by itself will replenish rebel forces with new recruits.

"A war is a process," he says, by way of explaining the apparent failure of the big rebel "final" offensive last January. "Never in the history of revolution has the first offensive been a victory." That the offensive did not touch off a massive popular uprising came as no surprise to him; government terrorism is a powerful deterrent.

"But if you don't think we have popular support," he asks, "who do you think feeds and hides our men?" While he concedes the theoretical possibility of a negotiated end to government repression and an eventual political accommodation, history does not nourish that hope.

That is the most important part of what Arene sees when he looks at El Salvador: a history of a half century or more of military dictatorships; a catalog of crushed hopes, promises reneged on, reformist juntas quickly eroding, election results rescinded. It is not a record that encourages confidence in "political solutions," he notes.

That is why he foresees a protracted, inconclusive struggle -- until somehow, the political, social and economic root causes of the opposition movement can be removed.