Who is Do Minh Kha from The Tears of Autumn and what is their importance?

Do Minh Kha is a section chief in the North Vietnamese intelligence service, Do is a cousin of the Ngo brothers who are running South Vietnam and more loyal to blood relations than to politics. While visiting Laos in September 1963, Do is observed b a U.S. paid spy spending three days with a young woman, later identified as his long-lost daughter, Dao/Nicole. She tells her father about the family's plan to kill John F. Kennedy, code named Lê Thu — "Tears of Autumn" — which is also the "death name" of Do's late wife. After leaving Laos, Do returns to Hanoi, where he meets a Cuban revolutionary, Manuel Ruiz, who presents Lee Harvey Oswald's dossier. The final logistics are then put in place.