Oscar Arias is a Costa Rican politician and diplomat, best known for serving as the President of Costa Rica twice, first from 1986 to 1990 and then from 2006 to 2010. He is recognized for his efforts in promoting peace in Central America during the 1980s, particularly through the Arias Peace Plan, which aimed to resolve conflicts in the region. In 1987, Arias was awarded the Nobel Peace Prize for his contributions to peace and democracy. His leadership emphasized social development, education, and environmental sustainability, making him a significant figure in both Costa Rican and international politics.