Washington — Despite assurances that he will not ''Americanize'' the El Salvador conflict, President Reagan faces a hard battle in Congress over the increased aid he is requesting for that country.
Part of the battle will be over conditions that a number of senators and congressmen want to attach to the proposed military aid.
Part of the battle will be over the way the President wants to obtain the money, taking some from appropriations originally destined for other nations.
At the end of the battle, Congress may cut the aid request to a degree and tighten, or extend, conditions already attached to Salvadorean aid. But some congressional specialists are predicting that once all these things are done - and once the air is cleared of a good deal of posturing and rhetoric on all sides - the President is likely to end up with most of what he asked for. The simple reason for acceding to the President's request, say supporters in the Congress, is that the majority of Congress does not want to see El Salvador taken over by leftist-led guerrillas.
In a speech Thursday to the National Association of Manufacturers, Mr. Reagan announced his long-awaited aid package for Central America. In calling for an additional $110 million in military assistance for El Salvador, the President argued the defense of El Salvador was in the national-security interest of the United States. He contended that the Soviet Union was attempting through Central America to ''tie down'' the US and limit its capacity to act in more-distant places such as Europe, the Gulf, the Indian Ocean, and the Sea of Japan.
Reagan said that the administration did not intend to ''Americanize the war'' in El Salvador, either with American soldiers or with ''a lot of US combat advisers.'' But he argued that the Salvadoreans' biggest need was for more military training. And his comments seemed to indicate that the self-imposed limit of 55 US military trainers working in El Salvador might be lifted if Congress didn't appropriate enough aid for Salvadoreans to be trained, on a more expensive basis, outside El Salvador. In other words, the President appeared to be saying: Give us more money, or we'll have to send more Americans to El Salvador on training missions.
''We think the best way is to provide training outside of El Salvador, in the US or elsewhere, but that costs a lot more,'' said Reagan. He asserted that US trainers had so far been able to train only 1 soldier in 10 in El Salvador and that this was one of the main reasons the military situation there was ''not good.'' The guerrillas, he said, had taken the ''tactical initiative.'' In a briefing for reporters on Reagan's speech, a senior administration official said that if the aid package was approved it would allow the Salvadorean government troops to regain the initiative.
Invoking the so-called domino theory, Reagan argued that if the guerrillas win in El Salvador, it will threaten other Central American nations and even Mexico.
''El Salvador will join Cuba and Nicaragua as a base for spreading fresh violence to Guatemala, Honduras, even Costa Rica. The killing will increase, and so will the threat to Panama, the canal, and ultimately Mexico,'' the President said.
Reagan disputed some critics who, he said, think ''our concern for security assistance means that all we care about is a military solution.'' He said that negotiations were a key part of American policy, but not negotiations that would be used as a ''cynical device for dividing up power behind the people's back.'' He endorsed a regional peace initiative being organized by Costa Rica, Honduras, and El Salvador.
The President also noted that more than three-quarters of US assistance to Central America and the Caribbean has been economic, not military. He said that he was asking the Congress for $168 million in increased economic assistance for Central America, of which $67 million would go to El Salvador.
The President did not place enough emphasis on negotiations, however, to satisfy many of his critics in the Congress.
''I can't imagine the Congress will give him everything he's asking for,'' said one congressional staff specialist who is a critic of the administration's Salvadorean policy. ''It would send a signal to the right wing in El Salvador and Guatemala that anything they do in the way of violence is all right with the US.''
One of the administration's most outspoken critics, Rep. Gerry E. Studds (D) of Massachusetts, says that if Reagan's new request was added to all of the military and economic aid sent to El Salvador since Reagan came to office, it would come to a total of about $150,000 per guerrilla. Mr. Studds is among the congressmen who advocate more efforts toward a ''dialogue'' with the opposition in El Salvador as well as more forceful criticism of right-wing violence.