 At the time , Diệm had little authority beyond the gates of his own palace . Bảo Đại had little confidence in him and gave him meagre support — the pair had clashed in the past , with Diem resigning as Bảo Đại 's Interior Minister two decades earlier , believing the head of state to be weak and ineffective . Many historians believe that Bảo Đại may have selected Diệm for the latter 's ability to attract U.S. support and funding . During the transition period , the French Expeditionary Corps maintained a presence in South Vietnam . This led to tension between France and the State of Vietnam . Diệm , a passionate nationalist , detested the French , who reciprocated , hoping he would fail , even calling for his removal on occasions . 
