Coup Atlas Research Database
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81703261975ConspiracyMilitary coup

Republic of Vietnam, 1975 — military coup conspiracy

Republic of Vietnam (VNM)Southeast Asia, AsiaMarch 26, 1975

Event Summary

This entry is coded 26 March 1975, at the height of the collapse of South Vietnam during the North Vietnamese 1975 Spring Offensive, in a period of intensifying pressure and plotting against President Nguyen Van Thieu. After the fall of Ban Me Thuot in mid-March, Thieu ordered a disastrous abandonment of the Central Highlands that turned into a rout along Route 7B, and by late March the northern provinces were disintegrating, with Hue and Da Nang falling in the last days of the month. As the military situation cratered, Thieu came under mounting political attack over corruption and his handling of the war, with the National Assembly, Catholic and Buddhist figures, and the U.

S. station chief all pressing for his removal, and former premier Nguyen Cao Ky secretly organizing a coup. This wave of resignation and coup pressure culminated in Thieu's resignation on 21 April 1975, days before the fall of Saigon on 30 April.

The March coding sits in this collapse-era plotting against Thieu.

Researched Details

Researched

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

Target identified in Coup Atlas research: Thieu resigned under pressure on 21 April 1975; South Vietnam fell to the North on 30 April 1975
RESEARCHED NAME
Key figures
President Nguyen Van Thieu (target of coup and resignation pressure)
Nguyen Cao Ky (former premier organizing a coup)
ARVN generals and civilian factions losing confidence in Thieu

Sources

On 21 April 1975, Thieu, under intense political pressure, resigned as president when his closest domestic allies began losing confidence over his handling of the war.
SOURCE REVIEWED Wikipedia: 1975 spring offensive open source ↗
After the fall of Ban Me Thuot, Thieu decided to abandon Pleiku and Kon Tum and redeploy, a withdrawal that collapsed amid a massive refugee flow and soldier desertions.
SOURCE REVIEWED Wikipedia: 1975 spring offensive open source ↗
Former premier Nguyen Cao Ky endorsed demands for Thieu's resignation and secretly began to organize a coup, with one CIA official recalling Ky said he would kill Thieu and take over.
SOURCE REVIEWED HistoryNet: Final Fiasco, The Fall of Saigon open source ↗
On 2 April 1975 South Vietnam's National Assembly accused Thieu of abuse of power, corruption and social injustice and called for a new government of national union, while the CIA station chief warned the country would collapse if Thieu was not removed.
SOURCE REVIEWED HistoryNet: Final Fiasco, The Fall of Saigon open source ↗

Editorial Note

No discrete plot is precisely dated 26 Mar 1975 in the sources located this session; the coding sits in the late-March 1975 collapse, when coup and resignation pressure against Thieu intensified (Ky organizing a coup, National Assembly and US pressure), culminating in his 21 April resignation. Context with strong framing. First Republic of Vietnam record in the run.

Cross-Reference

Only one dataset carries it. One of the three reference datasets we check against carries this event; the others do not list it. That is not a contradiction — the datasets cover different periods and use different thresholds — but it means the record has had less outside corroboration.

Identifiers for finding this same event in the other datasets:

Cline Center id
81703261975

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

Outcome and Target

Coup Atlas research identifies the target as: Thieu resigned under pressure on 21 April 1975; South Vietnam fell to the North on 30 April 1975.

Baseline coding: Plot discovered and disrupted before execution. 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

The Guardian

“Saigon Says Coup Fails,” March 27, 1975

New York Times

“Saigon Reports It Halted Plot to Overthrow Thieu,” March 27, 1975

Washington Post

“Coup Attempt: Thieu Says Retreat Is Over,” by Don Oberdorfer, March 27, 1975

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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