MEXICO CITY — NORTH American free-trade pact or not, Mexico is continuing a long tradition of charting its own course in foreign affairs.The United States joined the European Community last month in lifting economic sanctions against South Africa. Mexico did not. And Nelson Mandela, the spare, globe-trotting leader of the African National Congress, was in Mexico yesterday and is in Brazil today during a Caribbean and Latin American tour shoring up support for continued sanctions. "We ask you ... to apply all pressure against the white regime," Mr. Mandela told a large gathering of diplomats, intellectuals, and local politicians at the Mexican Foreign Ministry Monday. South Africa would like to buy Mexican oil and sell mining equipment here. But Mexico remains one of the few nations still maintaining a complete diplomatic and trading ban. Until the black majority gets the right to vote, sanctions will remain, Mexican officials say. South Africa is not the only example of sometimes stark US-Mexican foreign policy differences. Central America has been an area of contention throughout the 1980s. Mexico, for example, condemned the 1989 US invasion of Panama and still refuses to recognize President Guillermo Endara's right to rule. The Sandinista guerrillas had the full backing of Mexico when they overthrew dictator Anastasio Somoza Debayle in 1979. The Farabundo Marti National Liberation Front (FMLN) rebels in El Salvador have offices in Mexico. The US and Mexico butted heads over Cuba as recently as June, when Mexico sought the island nation's readmission to the Organization of American States, from which it was excluded in 1962. "We can create a favorable political climate in Cuba by stimulating trade and tourism and inviting the Cuban government to take part in international meetings," argued Mexican Foreign Minister Fernando Solana. The US opposed the move. But there is speculation that a North American free-trade pact may usher in an era of less conflictive US-Mexico policies. In June, a confidential cable sent to Washington from the US Ambassador to Mexico was leaked to the press. "From a foreign policy perspective, an FTA [free-trade agreement] would institutionalize acceptance of a North American orientation to Mexico's foreign relations. Just think of how this contrasts with past behavior.... If you listened to us in the UN or debating Central America you would have thought we were archenemies," wrote ambassador John Negroponte. The debate over "fast-track" in the US Congress and free-trade negotiations have already put a lid on disputes, says Cathryn Thorup at the Center for US-Mexican Studies, University of California, San Diego. "Both governments sense the brass ring out there and all other issues are subordinate." Ms. Thorup agrees with the Negroponte analysis. "Longer term, as their economic futures become more enmeshed, there'll be a tendency to see more eye to eye." But Jaime Gonzalez Graf, director of the Institute of Poltical Studies, a private think tank here, argues a free-trade pact makes it even more imperative that Mexico express its individuality. "It's a question of diplomatic consistency and tradition. As much as [Mexican President Carlos] Salinas [de Gortari] may want to alter this tradition, he can't," Dr. Graf says. "For example, the US would like Mexico to help bring down Castro," Graf says. "But I'm absolutely convinced Mexico would never do this. Not only because it would break a historic position, but because it would be an absolute submission to North American policy." Mexico's staunchly independent foreign policy has been shaped by the indelible memory of losing half its territory to the US in 1848 and as a response to a long economic dependence on its richer northern neighbor.