The Special Intelligence Service (SIS) was a covert counterintelligence branch of the United States Federal Bureau of Investigation (FBI) which operated in the Western Hemisphere, and primarily in Latin America during World War II. It was established to monitor the activities of Nazism in the Americas and pro-Nazi groups in Central and South America. SIS also investigated and collected Intelligence on agents of the Spanish Falange, the COMINTERN, and the Abwehr. The organization was a forerunner to the Central Intelligence Agency.