Three weeks before President John F. Kennedy's assassination, the president of South Vietnam, Ngô Đinh Diệm, was assassinated in a coup d'état along with his brother and top adviser, Ngô Đình Nhu. Speaking to Kennedy's brother-in-law, R. Sargent Shriver, President Johnson recalled his opposition to the Diệm coup when it was debated at the highest levels of the Kennedy administration.