The contra forces fighting in Nicaragua and the Sandinista government may soon decide that a negotiating table is a more promising forum than a battlefield. Faced with diminishing prospects that the Reagan administration, weakened by the Iran-contra affair, will be able to muster congressional majorities for sustained aid to the contras, key contra leaders and Central American governments are taking a closer look at possible diplomatic solutions to the six-year Nicaraguan contra war.
Meanwhile, new efforts to rejuvenate peace negotiations in Central America will be spearheaded by Javier P'erez de Cu'ellar, secretary-general of the United Nations, and Joao Baena Soares, secretary-general of the Organization of American States.
The two have announced plans to visit Central America in January in an attempt to breathe new life into the peace process sponsored by the ``Contadora'' group of four Latin nations - Colombia, Mexico, Venezuela, and Panama - plus the Contadora ``support group'' comprised of Peru, Argentina, Brazil, and Uruguay. The leaders of the two international organizations have indicated their willingness to provide peacekeeping units, electoral observers, and other services in support of the Contadora process.
Reagan administration officials say that in principle they support the idea of a negotiated solution to the Nicaraguan conflict but remain skeptical that the Managua government can be convinced to make necessary concessions, especially now that the contra aid program is in political trouble in Congress.
``Knowing how they stand with their own people, the Sandinistas could never open up the political process completely and allow elections,'' says retired Col. Lawrence Tracy, a former State and Defense Department official and author of two Reagan administration ``white papers'' on Nicaragua.
Even so, at least one source close to the contras says he is convinced that recent events have pushed key contra leaders toward a ``concrete and significant diplomatic initiative.''
This source, who asked not to be identified, says the logic of seeking a diplomatic solution has been reinforced by the Reagan administration's current political troubles at home - and by the ``profound opportunities'' created by the announcement that a group of Nicaraguan political parties is attempting to form a unified political slate to challenge the Sandinista government in municipal elections next year.
``A cease-fire under these conditions could galvanize the internal opposition into an all-out campaign that would test the willingness of the Sandinistas to accommodate a larger measure of political pluralism,'' this source says. ``Ironically, the contras could end up translating their current deepening problems into a major diplomatic coup.''
Another Washington analyst says he looks for a Central American peace initiative. This expert, who also asked not to be identified, says the nations of the region, now convinced that the contras cannot win a military victory, are actively seeking another means to force an end to the fighting that has contributed to six years of turmoil throughout the region.
``They're resigned to the fact that the administration is not going to pull their chestnuts out of the fire,'' the analyst says. ``So on their own they're going to talk'' to the Sandinista government.
Central America experts say one promising model for a regional peace initiative was put forth last January by the six main Nicaraguan opposition parties. Under the proposal, the Sandinistas would agree to a cease-fire and talks leading to a general amnesty for the contras and to the restoration of all civic and political rights.
The plan drew equivocal support from Managua and Washington. Sources familiar with the contra issue say some variation on the six-party plan might now fall on more receptive ears in both capitals.
The plan did win open support from contra leader Arturo Cruz, who later said he would be willing to ``delegate'' responsibility for a dialogue to the internal Nicaraguan parties.
In an interview last week, Mr. Cruz, who now lives in Miami, reaffirmed his willingness to give that kind of authority to the internal Nicaraguan opposition as part of a ``comprehensive, simultaneous, and verifiable'' peace plan.
Advocates of such a plan say it represents a no-lose proposition for the Reagan administration.
If the Sandinista government agrees to a plan containing suitable guarantees, the United States would achieve the diplomatic objective cited both by Reagan officials and contra leaders as the principle raison d'^etre of the contra aid program - democratic reform inside Nicaragua leading to political participation of all parties.
If the Sandinistas rebuff such a plan, moderate Democrats and Republicans in Congress - who comprise the swing vote on contra aid and favor negotiations over military action - would be far more likely to support future administration policy on Central America.
Moreover, the alternative to a peace plan could be a no-win proposition for the Reagan administration, advocates say. The decision to go for more contra aid means bruising new congressional fights. A legislative defeat would deal a crippling blow to the foreign policy of an already weakened President Reagan. And even a victory would be hedged about with important congressional constraints.
``In the best case, Reagan ends his term with an insufficient amount of money, congressional restrictions, majority public disapproval, and allied opposition,'' one congressional source says. ``That's not a very promising way to escalate a war.''
Finally, note advocates, failing to sponsor a peace proposal could force the Reagan administration to choose between direct US intervention in Central America - a policy destined to provoke a firestorm of domestic and international criticism - or leaving office with the Sandinistas in a dominant political and military position.
In August Congress approved $100 million in mostly military aid to the contras, $60 million of which is now in the pipeline for the purchase of supplies and small arms. Congress is expected to approve disbursement of the remaining $40 million, most of which will be spent on heavy artillery, in February.
A tougher political fight is expected in the spring when the administration comes back to Congress for additional funding for the rebels.