Washington — It may take months to sort out the lasting significance, if any, of Monday's government-guerrilla ''summit'' meeting in El Salvador. At time of writing, the talks were still under way. But no matter where they lead, President Jose Napoleon Duarte is seen here as having taken the initiative in a bold move toward resolving the Salvadorean conflict.
In addition, Reagan administration officials can already perceive a strong public relations plus for Washington emerging from the event. Duarte's move has deflected attention from President Reagan's troubles in the region and placed the emphasis on peace talks.
There are dangers for the Reagan administration, too, in Duarte's approach. His high-profile meeting with the guerrillas in the northern Salvadorean town of La Palma could raise unrealistic expectations. It could create a negotiating mood and momentum within long-suffering El Salvador that might be difficult for Washington to influence or control.
The La Palma meeting also tends to confer a certain legitimacy on the guerrilla forces that they did not have before in the eyes of some foreigners as well as Salvadoreans. As Ruben Zamora of the guerrillas' political front argued last week, ''This meeting is recognition by President Duarte that there are two powers, two armies, and two territories in El Salvador.''
For President Duarte, the meeting has offered an opportunity to create a new consensus among his divided supporters. But should the negotiating process move too quickly to suit the Duarte government's powerful military men, Duarte could find himself in serious trouble.
For the guerrillas, too, there is always the possibility that the talks will cause longstanding factional conflicts to reemerge.
In a speech at the University of Alabama Monday, Reagan called the La Palma meeting a ''historic endeavor in the cause of peace in Central America.''
''President Duarte is participating at great personal risk ... a risk worth taking,'' said Reagan.
The Reagan administration had been on the diplomatic defensive in Central America recently. It appeared to be at odds with the four nations of the Contadora group - Mexico, Colombia, Venezuela, and Panama - over US-proposed modifications in a draft regional peace treaty. Last week, the US Congress voted to suspend the administration's ''covert'' aid to rebels fighting the Sandinistas in Nicaragua.
Walter Mondale, the Democratic Presidential nominee, has attempted to make Central America an election issue. Mondale has charged that no meaningful negotiations were under way in Central America and that President Reagan, through an ''illegal war'' against Nicaragua, was leading the entire region toward war.
In El Salvador itself, according to the Reuters news agency, the most optimistic forecasts by diplomats were that the meeting might result in a truce.
Differences between Duarte and the guerrillas remain deep and perhaps unbridgeable. Duarte offers the guerrillas a chance to participate in constituent assembly elections. But the rebel leaders have been calling for a share in power as a precondition for a negotiated settlement.
Guillermo Manuel Ungo, a participant in the La Palma meeting on the guerrilla side, warned that ''there can be no magic formula which can be achieved in one day.''
And just days before the meeting, the leading guerrilla military leader, Joaquin Villalobos, who announced at the last minute that he would not attend the talks, vowed to maintain military pressure on the government forces.
''We are going to keep ourselves on the offensive in the military struggle,'' said Villalobos on the rebel Radio Vinceremos.