Arrest and assassination of Ngô Đình Diệm

On 2 November 1963, Ngô Đình Diệm, the president of South Vietnam, was arrested and assassinated in a CIA-backed coup d'état led by General Dương Văn Minh. After nine years of autocratic and nepotistic family rule in the country, discontent with the Diệm regime had been simmering below the surface and culminated with mass Buddhist protests against longstanding religious discrimination after the government shooting of protesters who defied a ban on the flying of the Buddhist flag.

The Army of the Republic of Vietnam (ARVN) launched a bloody overnight siege on Gia Long Palace in Saigon. When rebel forces entered the palace, Diệm and his adviser and younger brother Ngô Đình Nhu were not present, having escaped to a loyalist shelter in Cholon. The brothers kept in communication with the rebels through a direct link from the shelter to the palace, and misled them into believing that they were still in the palace. The Ngô brothers soon agreed to surrender and were promised safe exile. After being arrested, they were instead assassinated in the back of an armoured personnel carrier by ARVN officers on the journey back to military headquarters near Tân Sơn Nhứt Air Base.

While no formal inquiry was conducted, the responsibility for the deaths of the Ngô brothers is commonly placed on Minh's bodyguard, Captain Nguyễn Văn Nhung and on Major Dương Hiếu Nghĩa, both of whom guarded the brothers during the trip. Minh's army colleagues and US officials in Saigon agreed that Minh ordered the assassinations. They postulated various motives, including that the brothers had embarrassed Minh by fleeing the Gia Long Palace, and that the brothers were killed to prevent a later political comeback.

The generals initially attempted to cover up the assassination by suggesting that the brothers had committed suicide, but this was contradicted when photos of the Ngôs' corpses surfaced in the media.