US plotted to capture the Ngo family and destroy the Saigon Palace

By Desmond Okafor · August 17, 2026

Top Secret plans from August 1963 show Washington weighing the use of combat forces and the destruction of a palace to ensure the fall of the Ngo family.

Vietnamese generals faced preemptive assassination and American dependents in Saigon were viewed as potential pawns in a blackmail game. The cost of these calculations was a planned path toward a bloodbath in the streets of the capital.

In a Top Secret memorandum dated August 30, 1963, Assistant Secretary of State for Far Eastern Affairs Hilsman laid out a contingency map for the removal of South Vietnamese President Ngô Đình Diệm and his brother Nhu. The document, sent to the Secretary of State, reads like a manual for a managed collapse. It does not weigh the stability of the Vietnamese state or the lives of its citizens; it weighs the speed of a coup against the potential for American embarrassment.

Gotterdammerung in the Palace

Hilsman used a heavy word for the final stage of his plan: "Gotterdammerung." In the twilight of the gods, the United States would not seek a negotiated peace or a diplomatic exit. Instead, the memorandum suggests that Washington should "encourage the coup group to fight the battle to the end and to destroy the Palace if necessary to gain victory."

The terms for the Ngo family were to be "unconditional surrender." The coldness of the phrasing reveals a total abandonment of the man Washington had spent years propping up. For the Nhu family, the proposed solution was banishment to France or another European country. For Diệm, the man who according to the public record served as the first president of South Vietnam, the memorandum is chillingly vague. Hilsman wrote simply: "Diem should be treated as the generals wish."

Jamming Radios and Blowing Bridges

To ensure the coup succeeded, the United States was prepared to move beyond diplomatic support into active sabotage. If hostilities broke out between the government and the coup group, the objective was "crystal clearness": bring the entire Ngo family under the control of the rebels.

The memorandum outlines a suite of tactical interventions to isolate the president. The U.S. would "jam radio communications between Diem and these forces" and "encourage interdiction of transportation by blowing up bridges." This was not a plan to support a democratic transition, but a blueprint for a military strangulation. Hilsman even suggested the "prompt capture and removal" of family members outside Saigon, specifically targeting Can and Thuc in Hue, promising that the U.S. would assist "to any extent necessary."

A Two-Edged Game

Washington’s fears were not just about the internal dynamics of Saigon, but about how Diệm might play the Cold War map to survive. Hilsman flagged the possibility of Diệm making a political move toward the Democratic Republic of Vietnam (DRV) in the North or appealing to Charles de Gaulle for neutralization.

The U.S. response was to treat any such move as a betrayal to be weaponized. Hilsman proposed that the U.S. "publicize to the world at an appropriate moment any threats or move by Diem or Nhu toward the DRV" to show the "two-edged game they are playing." This propaganda effort was designed specifically to "justify publicly our counteractions."

The memo further notes that if the DRV responded to the coup by sending troops into the South, the U.S. would "hit the DRV with all that is necessary to force it to desist." The human stakes were scaled up from the Palace to the entire region, with Hilsman insisting that the U.S. be "prepared to take such military action."

August 30, 1963

The memorandum reflects a period of extreme tension where American personnel were viewed as liabilities. Hilsman considered the possibility of "mysterious deaths" of U.S. dependents used as blackmail by the Ngo family. In response, he suggested issuing arms to selected American personnel and maintaining a state of "sangfroid" in the face of threats.

The document frames the potential use of U.S. combat forces not as a last resort for peace, but as a tool to "assist the coup group to achieve victory" if the bloodbath in Saigon became too prolonged. The priority was speed; the priority was the removal of the Ngo family; the priority was the success of the coup at any cost.

This memorandum was written just two months before the event it anticipated. In November 1963, the CIA-backed coup took place. Ngô Đình Diệm and his brother Nhu were captured and assassinated, fulfilling the memorandum's directive that the president be treated as the generals wished.