Are we beginning to see some promising moves toward a solution of the growing turbulence in Central America? Possibly. The Reagan administration was disappointingly lukewarm when Mexican President Lopez Portillo first proposed a peace plan for the Salvadoran conflict. It is therefore significant that Washington is now pursuing the idea, and has authorized Mexico to submit to Cuba and Nicaragua some US proposals for normalizing US relations with those countries. ''We feel hopeful that a process of negotiations may be starting in the Caribbean,'' commented Mexican Foreign Minister Jorge Castanneda following two meetings with US Secretary of State Haig.
It is too early for more than a quiet cheer, of course. Possibly Mr. Haig is motivated less by genuine enthusiasm for the Lopez Portillo plan than by feeling constrained to go along with a country that is playing an increasingly dominant role in the region. Nonetheless, those who are deeply concerned about the United States falling into the trap of another Vietnam will want to support a policy focusing on international negotiation rather than armed intervention. The essence of the US proposals, according to Mr. Castanneda, is a series of nonaggression pacts between Nicaragua and its neighbors, together with US guarantees not to intervene in Nicaragua.
Such agreements would make sense. They would address Washington's legitimate security concern that Marxist governments controlled by Cuba and the Soviet Union are being implanted on its back doorstep. They would address the Nicaraguan and Cuban concern that the United States seeks to prevent social and political change in Central America, by force of arms if necessary. Not unreasonably Nicaragua and Cuba could be asked to end any military involvement in El Salvador in return for a US promise not to permit the training of exile forces in Florida and elsewhere that aim at overthrowing the Sandinista revolutionary government.
Letting Mexico, Venezuela, and other countries of the region help carry the diplomatic ball would show maturity of judgment. After so many decades of US hegemony in Latin America, the time has come for the hemispheric nations to control their own affairs and resolve their own conflicts. US policy should encourage such a trend.
It in fact is cause for concern that high US officials now talk of the Central American tensions as a ''global issue'' requiring direct negotiation with the Soviet Union. Why elevate this limited regional conflict to the magnitude of an East-West confrontation and give the Russians a weight in Central American affairs they do not actually have? Why hand them a potential diplomatic bargaining chip? It might be imagined, for instance, that Moscow would propose ''staying out'' of Central America (where it does not appear to have that much influence) in return for the US ''staying out'' of Poland. That would be a ridiculously unequal tradeoff, to say the least. No one could disagree that Poland is by far and away the more important strategically in the East-West balance.
Mexico's mediation effort, in short, offers an imaginative way out of the Central American dilemma. The Reagan administration is right to be testing it.