With the Geneva Agreement, Vietnam gained independence from France, and the country was separated into a northern zone governed by a Communist leader, and a southern zone ruled by an anti-communist leader. But this division was intended to be temporary because, according to the agreement, there was to be an election in 1956 to decided whether to reunify the country or not.
However, the anti-communist leader, Ngo Dinh Diem, who was not as popular among people like the communist government, refused to hold the elections, and the U.S. supported this decision mainly because It feared that if elections were held, the Communist government would win and the Domino Effect would take place: Communism would spread in South East Asia as well.
