DIPLOMACY : Chile’s Renewal of Full Ties With Cuba Deals Blow to U.S. : Socialist partners pressed President Frei on relations.

The recent renewal of full diplomatic relations between Santiago and Havana has reaffirmed growing acceptance of Cuba among Latin American nations despite continuing U.S. efforts to isolate President Fidel Castro’s Communist government.

Now, the only Latin American countries that do not have full diplomatic ties with Cuba are Guatemala, El Salvador, Costa Rica, the Dominican Republic and Paraguay. Only the United States maintains a trade embargo.

“We are totally and embarrassingly isolated on this issue,” said Wayne Smith, a professor at Johns Hopkins University and former U.S. diplomat.

“Chile joins with other countries of Latin America in trying through engagement to bring Cuba around to a more open political system,” Smith said by telephone from Washington.

The United States broke diplomatic relations with Cuba in January, 1961, two years after Castro took power in a revolution. At U.S. urging, the Organization of American States excluded Cuba in 1962 for supporting armed revolutionaries in other countries. By late 1964, all Latin American governments except Mexico’s had cut ties with Havana.

The late President Jorge Alessandri, a conservative, broke Chilean relations with Cuba in August, 1964, less than a month before the election of Eduardo Frei Sr. Relations were not restored under Frei, a Christian Democrat.

But Salvador Allende, a Socialist allied with Communists, re-established full diplomatic relations with Cuba after taking office in December, 1970.

Chile’s armed forces, led by Maj. Gen. Augusto Pinochet, seized power in a coup on Sept. 11, 1973. On Sept. 14, Pinochet expelled 150 Cubans and broke relations with Havana. Later, many exiled Chilean leftists moved to Cuba.

Meanwhile, one by one, other Latin American governments began renewing their Cuban relations, responding to conciliatory overtures by Castro. As the region’s military governments gave way to civilian ones through the 1980s, and as the Cold War fizzled out, Cuba further expanded its ties.

Pinochet gave up power in 1990, and in July, 1991, civilian President Patricio Aylwin established consular relations with Cuba. Since then, Chilean companies have invested about $40 million in Cuba, while trade between the two countries amounts to $15 million a year--almost all Chilean exports.

The coalition government of President Eduardo Frei Jr., a Christian Democrat who succeeded Aylwin in 1994, includes the Socialist Party, which has strongly advocated full diplomatic relations with Havana.

When full relations were announced April 7, the Socialists were jubilant. Clodomiro Almeyda, who was a foreign minister under Allende, told reporters that the move was especially significant “at a time when Cuba faces an escalation of the illegal and inhuman American blockade.”

Opposition politicians expressed concern that renewal of the ties might spark U.S. congressional opposition to plans by the U.S., Canadian and Mexican governments for Chile’s entry into the North American Free Trade Agreement.