Robert Strange McNamara (/ˈmæknəmærə/; June 9, 1916 – July 6, 2009) was an American business executive and the eighth United States Secretary of Defense, serving from 1961 to 1968 under Presidents John F. Kennedy and Lyndon B. Johnson. He remains the longest serving Secretary of Defense, having remained in office over seven years. He played a major role in promoting the United States' involvement in the Vietnam War. McNamara was responsible for the institution of systems analysis in public policy, which developed into the discipline known today as policy analysis.