ocr: Chile's most important relationship remains with its main trading partner, the USA, which supplies 95% - of materials for the critical copper industry. The relationship has not always been easy. Under Allende, the USA actively workedagainst the government, fearing that the spread ofsocialism wouldjeopardize its investments in Chile and the rest ofLatin America. Pinochet's human rights record eventually became an embarrassment to the Reagan administration, which qualifiedits backang for him. Present relations are good; the Frei government concurs with US economic and: regional policy in Latin A ...