Cuban involvement in El Salvador's civil war is now established beyond any doubt. And the Reagan administration's carefully orchestrated diplomatic offensive to convince Western Europe and Latin America of the Cuban role is yielding results.
Although most of Latin America counsels Washington to keep US troops out of the struggle, the hemisphere is increasingly sympathetic to sharply stepped-up US military assistance to the embattled military-civilian government in San Salvador.
A number of governments are looking seriously at their own diplomatic relations with Havana. It is known, for instance, that several countries have considered pulling out their ambassadors in protest over the Cuban shipment of arms to Salvadoran guerillas. And Cuban embassies in Latin America have been told of their host governments' displeasure over the Cuban role in El Salvador.
All this comes as Washington releases its "white paper" on the Cuban role, which outlines "the direct Cuban involvement."
The US makes these points:
* The political direction, organization, and arming of the Salvadoran insurgents are coordinated and strongly influenced by Cuba, with the active assistance of the Soviet Union, East Germany, and Vietnam.
* Cuba has also served as a major collector of arms for the Salvadoran guerillas -- shipping at least 200 tons of weapons, ammunition, and military devices during the past 18 months and promising more than 600 additional tons.
* In contrast, from 1977 to January of 1981, the United States did not supply arms or ammunition to the Salvadoran government, and limited US military aid, resumed in 1980, was nonlethal equipment.
[In January, 1981, former President Jimmy Carter authorized $5 millin additional military assisance for combat equipment, including rifles, ammunition , and grenade launchers.]
* The Salvadoran rebels and the Cubans have done all they could to mask the arms flow and to give the guerilla cause a non- Marxist political orientation that they hoped would -- and did -- encourage support of the guerillas by some Latin American governments.
* This effort to mask the arms transfers included shipment of vast quantities of arms of US origin -- captured by the North Vietnamese and the Viet Cong during the Vietnam war.
* Nicaragua's Sandinista leadership has been closely linked to the arms flow and one member of the all-powerful Sandinista directorate, Bayardo Arce Castano, is singled out as particularly involved.
[Reuters reported from Moscow Feb. 24 that Cuban leader Fidel Castro is said to have denied that Cuba is shipping arms to Salvadoran guerillas. A Soviet official told a press conference that Dr. Castro, in speech before the Soviet party congress, denied providing arms.]
The reaction to all these disclosures has been quick throughout Latin America. Already the governments of Panama and Venezuela -- which had supported the Sandinista effort to topple the government of Gen. Anastasio Somoza Debayle in Nicaragua and were supportive of the guerrilla efforts in El Salvador -- have pulled back.
In fact, the Venezuelans have for some months now been giving verbal support to the junta. Salvadoran President Jose Napoleon Duarte is well known in Venezuela, having spent eight years in exile in Caracas during the 1970s. Now Venezuela is considering support beyond the verbal.
None of these governments favor direct US military intervention. Their traditions of non- intervention, written into their national psyches as well as hemisphere protocols, argue against a military role. But they are clearly sympathetic to Washington's effort to beef up the Salvadoran Army.
They also counsel the US not to overlook the economic and social reforms that in their view are necessary for El Salvador. They were pleased with a State Department comment the other day supporting those reforms.
Many Latin Americans were suspicious of the US evidence on Cuban involvement, but now that they have seen it they clearly accept it as authentic. The US case is based on documents captured from factions of he splintered Salvadoran Communist Party during raids by the Salvadoran military last Noveber and January. It is corroborated by other evidence.