Ngo Dinh Nhu
Ngo Dinh Nhu was the brother and chief political adviser to Ngo Dinh Diem, President of the Republic of Vietnam. He headed the semisecret Can Lao party and its more public subsidiaries. Both were overthrown and killed in November 1963 coup. Since Diem himself was a bachelor, Nhu's wife, born Tran Le Xuan but usually called Madame Nhu, acted as official hostess and was extremely visible.
While he was principally a counselor rather than executive, Ngo directed the Strategic Hamlet Program, which the U.S. and other countries regarded as an important metric of the progress of the anti-communist repression in South Vietnam. He could be an effective organizer, certainly of political groups and arguably of the Strategic Hamlets program. The pilot hamlet, in Operation SUNRISE, however, was not a success.
Stanley Karnow, who knew him, said "he appeared to me to be approaching madness." Karnow, as opposed to Sheehan, was not sure if Ngo was an opium user, but had many of the mannerisms of one.  Neil Sheehan describes him as "an intellectual with a corrosive wit, as slim and handsome as Diem was plump and waddling, and a bit daft in his love of power and scheming. Lucien Conein called him "Smiley" after what seemed a mask-like expression.
He was given to inflammatory rhetoric, not only in the Buddhist Crisis. According to Sheehan, "Nhu would hold forth to Conein on the magnificence of Hitler's charisma in stirring up the German people and keeping them entranced." 
Nhu headed a semisecret political party for his brother, based on his modifications of a French-originated theory called personalism. The concepts came from his education at the Ecolee de Chartres in France, and his subsequent work as an archivist there and at the Imperial Archives in Hue. He was fascinated by totalitarian government and admired Adolf Hitler, but also liked the organizational ideas of Karl Marx and Vladimir Lenin, and admired the discipline of his Vietnamese Communist opponents. 
His synthesis was the Can Lao, more a secret society than, as it has been described, a political party. In addition, he probably drew inspiration from the Kuomintang. He also formed a mass movement, called the Blue Shirts, that was used in some of the ways Hitler had used the Brown Shirts, or Sturmteilabtung to form public opinion and deference to authority.
His brother Diem, who was a strict moralist, closed Saigon's opium trade in 1955, although there may have been power-based reasons as well: Diem was also shutting down the Binh Xuyen, which controlled much crime in Vietnam. There were substantial reports that Nhu, by 1958, used the drug trade to support his political activities. Part of the flow of opium may have used the South Vietnamese Air Force, under the command of Nguyen Cao Ky. It is not known if Diem was unaware of these activities or chose to ignore them.
Role in government
Robert McNamara said that Diem used Nhu to contact Ho Chi Minh in the fall of 1963.  His role in initiating the Buddhist Crisis of 1963 is not completely clear, although he was definitely involved in its escalation.
As the crises of 1963 deepened, it became U.S. policy that while Diem might be able to continue effectively, Nhu had to go. Ambassador Frederick Nolting, however, felt this was as politically impossible as asking John F. Kennedy to get rid of his brother, Robert Kennedy. McNamara said CIA Station Chief John Richardson had said that while Diem was respected and moral, people around him, especially Nhu, were ruining his reputation and creating tragedy. 
- Karnow, Stanley (1983), Vietnam, a History, Viking Press, p. 265
- Sheehan, Neil. (1988), A bright shining lie: John Paul Vann and America in Vietnam, New Random House, pp. 178
- Karnow, pp. 265-266
- Sheehan, pp. 178-179
- McCoy, Alfred W.; Cathleen B. Read & Leonard P., II Adams (1972), The Politics of Heroin in Southeast Asia, Harper Colophon,p. 153
- Robert S. McNamara (1995), In Retrospect: the Tragedy and Lessons of Vietnam, Times Books division of Random House, p. 51
- McNamara, p. 75