Whose Hand in El Salvador?

THE trail of responsibility for the guerrilla assault in El Salvador runs back through Nicaragua to Cuba. In the case of Nicaragua's President Daniel Ortega Saavedra it is the second double-cross in a matter of days of those who seek peace in Central America. First Ortega abruptly ended his cease-fire with the contras, the anti-communist guerrillas who oppose his rule in Nicaragua. Now he has actively supported the pro-communist guerrillas launching an assault in El Salvador.

Nicaragua's support of the offensive is clear. Radio traffic crackles between a command center in the Nicaraguan capital of Managua and the rebels in the field in El Salvador. Arms, ammunition, and other supplies move from Nicaragua to El Salvador. Last month a truck carrying automatic weapons, ammunition, and rockets was intercepted in Honduras en route from Nicaragua to the Salvadoran rebels. Honduran officials say the driver admitted having made monthly runs for more than a year.

Such Nicaraguan armed support for the Salvadoran rebels is, of course, in direct conflict with Nicaragua's pledges to work for peace in Central America.

But experts see Ortega as merely the enthusiastic funnel for weaponry, support, and inspiration from Cuba for the Salvadoran Marxists.

Cuba now has a plant for the manufacture of AK-47 automatic rifles and ammunition, and these Cuban-made weapons are turning up in Salvadoran rebel hands. Both the Salvadoran guerrillas and the Sandinistas have long had close links with Cuba, have trained under Cuban advisers, have taken political direction from Cuba, have been supplied by Cuba.

The intriguing question is whether Cuban-encouraged unrest in El Salvador is fomented in concert with the Soviets, or in defiance of them.

The United States has been leaning on the Soviet Union to cut back its military aid to Cuba and Nicaragua. If there is genuine reform in Moscow, goes the American argument, that should be manifested in a more peaceful and constructive Soviet approach to Central America. President Bush will undoubtedly want to talk more about Central America with Mikhail Gorbachev when the two meet for their non-summit in the Mediterranean next month.

It is that meeting, and the peace and change breaking out in Eastern Europe, that is so depressing to Mr. Castro. He is on record with his disgust for the movement of various East European countries away from communism. Castro's brother Raul in Belgrade last month said Cuba was opposed to a new relationship between the superpowers that would change the ideological and military status quo in Europe.

Castro has been bitterly critical of what he believes is Mr. Gorbachev's reformist trend in the Soviet Union. The personal chemistry between the two men is not good. As Gorbachev has introduced glasnost and perestroika, Castro has increasingly demanded austerity in Cuba and adherence to hard-line Marxist-Leninist principles.

In so doing, he has become increasingly irrelevant and isolated in the communist world. Becoming alienated from Moscow was problem enough; now with major changes under way throughout East Europe, he is threatened with increased loss of support.

That has very practical implications. Cuba's economy is hard-pressed. The possible loss of aid from, and perhaps trade with, Eastern European countries is bad news for Cuba.

Could it be that Castro's green light for new upheaval in Central America is an attention-getter from a fading communist leader who sees a changing communist world passing him by? The guerrilla assault in El Salvador looks like a desperate gamble against a well-armed and supplied Salvadoran army. If there is little prospect of military victory, the men who sanctioned the attack must have done so with great cynicism.

Where is the logic in all this? ``Ah, my friend,'' says one well-informed Central American expert, ``you are looking for logic where there is no logic. These men are fanatics.''