Various courses of action towards Vietnam were discussed, such as fostering a regime change or taking a series of selective measures designed to cripple the influence of Ngô Đình Nhu, Diệm's brother and chief political adviser. Nhu and his wife Madame Ngô Đình Nhu were seen as the major causes of the political problems in South Vietnam. The inconclusive result of Krulak and Mendenhall's expedition resulted in a follow-up mission, the McNamara–Taylor mission.