Arias Sanchez, Oscar (1940– )

Costa Rican politician, president 1986–90 and from 2006, and secretary general of the left-wing National Liberation Party (PLN) from 1979. He advocated a neutralist policy and in 1987 was the leading promoter of the Central American Peace Plan, which brought peace to neighbouring Nicaragua. He lost the presidency to Rafael Angel Caldéron Fournier in 1990. He was awarded the Nobel Prize for Peace in 1987 for promoting peace in Central America.

Educated at universities in Costa Rica, the USA, and the UK, he taught political science at the University of Costa Rica 1969–72 before holding ministerial posts under President José Figueres Ferrer and serving congress 1978–82. From 1990 he led the Arias Foundation for Peace and Human Progress.