Thieu, Nguyen Van (nəwēˈĕn vän tēˈō, tyō) [key], 1924–2001, president of the former Republic of South Vietnam (1967–75). After World War II, he joined the Viet Minh, but then left it to join what became the South Vietnamese National Army (ARVN). He rose rapidly, becoming a division commander. In 1963, he helped lead the coup overthrowing President Diem. Together with Nguyen Cao Ky, Thieu was a leading force in a succession of South Vietnamese governments from 1963 to 1967. He was elected president in 1967 and retained office in a rigged election in 1971. Thieu was reluctant to sign the Paris Agreement (1973) until promised U.S. military aid. When North Vietnam launched an offensive in 1975 (see Vietnam War), no aid was forthcoming, and Thieu abandoned the northern half of the country, leading to a rout. He went into exile a few days before the Communist victory.