Coup Atlas Research Database
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81709131964AttemptedMilitary coup

Republic of Vietnam, 1964 — military coup attempt

Republic of Vietnam (VNM)Southeast Asia, AsiaSeptember 13, 1964

Event Summary

Before dawn on 13 September 1964 Generals Lam Van Phat and Duong Van Duc sent dissident units into Saigon in a coup attempt against the ruling military junta of General Nguyen Khanh in South Vietnam. Phat, recently dismissed as interior minister, and Duc, about to be removed as IV Corps commander, both Catholics pushed out partly under Buddhist pressure, recruited some ten battalions and seized key points, and Phat announced over the radio that Khanh was a traitor to be arrested. But the coup was poorly planned and coordinated and won little support from other generals or the populace.

Khanh evaded capture, and with clear United States backing and the crucial support of the younger officers around air commander Nguyen Cao Ky and General Nguyen Chanh Thi, he rallied loyal forces. The coup collapsed by the next morning without casualties, though the crisis further weakened Khanh and strengthened the rising Young Turk generals.

Researched Details

Researched

Independent research, added record by record. Hover any label for what it means.

Target identified in Coup Atlas research: General Nguyen Khanh survived the coup attempt with U.S. and Young Turk support, though his position was weakened
RESEARCHED NAME
Key figures
Nguyen Khanh (junta leader of South Vietnam, target)
Lam Van Phat and Duong Van Duc (coup leaders)
Nguyen Cao Ky (air commander who backed Khanh)

Sources

The September 1964 South Vietnamese coup attempt took place before dawn on September 13, 1964, when the ruling military junta led by General Nguyen Khanh was threatened by a coup headed by Generals Lam Van Phat and Duong Van Duc, who sent dissident units into Saigon.
SOURCE REVIEWED Wikipedia, September 1964 South Vietnamese coup attempt open source ↗
They captured various key points and announced over national radio the overthrow of the incumbent regime, but with the help of the Americans Khanh was able to rally support and the coup collapsed the next morning without any casualties.
SOURCE REVIEWED Wikipedia, September 1964 South Vietnamese coup attempt open source ↗
The coup failed because of inadequate prior planning and coordination, lack of support from within the military and from the populace, and clear and unequivocal US support for the Khanh government.
SOURCE REVIEWED U.S. State Department, Office of the Historian open source ↗
With the backing of Air Marshal Nguyen Cao Ky and General Nguyen Chanh Thi, Khanh was able to force Phat and Duc to capitulate the next morning, September 14.
SOURCE REVIEWED Wikipedia, September 1964 South Vietnamese coup attempt open source ↗

Editorial Note

Date match, well documented. Dataset codes it a military coup and leader remained in office, both accurate. Part of the turbulent run of Saigon coups after the November 1963 overthrow of Diem.

Cross-Reference

Datasets agree. At least two of the three reference datasets we check against carry this event, and none of them disagrees about its date or its result.

Identifiers for finding this same event in the other datasets:

Cline Center id
81709131964
Albrecht/Koehler/Schutz (CAM) id
CAM-817-1964-09-13-2

How the match is made is described in crossref-report.md.

Outcome and Target

Coup Atlas research identifies the target as: General Nguyen Khanh survived the coup attempt with U.S. and Young Turk support, though his position was weakened.

Baseline coding: Coup attempt failed to remove the incumbent. Recorded leader fate: remained in office; not physically harmed. The baseline file does not name individual targets; researched names are kept in a separate layer.

Baseline Dataset Citation

Cline Center Coup d’État Project Dataset, v2.2.2
Peyton, Buddy, Joseph Bajjalieh, Michael Martin, and Andrea Gerald. 2026. Cline Center Coup d’État Project Dataset. Cline Center for Advanced Social Research. V.2.2.2. February 17. University of Illinois Urbana-Champaign. doi: 10.13012/B2IDB-9651987_V10
⚑ This citation establishes the coded baseline record; use the claim-level sources above for the researched narrative.

Baseline Source-Document Entries

CSP

Named in the baseline source document; no article citation was recorded.

Wikipedia

New York Times

“VIETNAM’S Faiths Underlie Rising Buddhist-Catholic Disputes Sharpened Under Diem,”by David Halberstam, September 14, 1964

This is the citation trail carried by the baseline dataset, grouped by outlet and rejoined from the line-wrapped original. Coup Atlas has not independently re-checked every document; read the original before citing a specific claim. URLs the import damaged beyond safe repair are shown as plain text and listed in citations-report.md. How this list is built →

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