---
category: "Intelligence Operation"
tags:
  - Program
  - Vietnam
  - PsychologicalWarfare
  - Counterinsurgency
  - SouthVietnam
  - USArmy
summary: "South Vietnamese defection and amnesty program of the Vietnam War, the main channel for US psychological operations leaflets and loudspeaker broadcasts aimed at Viet Cong and North Vietnamese soldiers."
location: South Vietnam
created: 2026-06-04
updated: 2026-06-04
---
Chieu Hoi, meaning "open arms" in Vietnamese, was the official defection and amnesty program of the [[South Vietnam|Republic of Vietnam]] government, running throughout the [[Vietnam War]]. It offered Viet Cong and [[People's Army of Vietnam|North Vietnamese Army]] personnel who surrendered amnesty, resettlement support, and reintegration into South Vietnamese society. The program became the central organizing framework for [[U.S. Army]] psychological operations in Vietnam: the appeal to defect under Chieu Hoi was the dominant message in American psywar leaflet drops, loudspeaker broadcasts, and aerial operations.[^1]

### US Psychological Operations Integration

In March 1969 alone, 713 million leaflets were dropped over Vietnam. [[Col. Emmett O'Brien]] of the [[US Army War College]], in a 1971 paper on defection, described the defection process in five phases: inducement (persuading the subject to consider defection); reception and interrogation (processing the defector upon surrender); training (ideological and practical reorientation); resettlement and employment (integration into South Vietnamese society or the armed forces); and follow-up (monitoring and support).[^1]

The [[Army Concept Team in Vietnam]], which studied US psyop output to evaluate effectiveness, analyzed the distribution of effort across the overall leaflet and broadcast campaign. Approximately 55 percent of output was directed at Chieu Hoi appeals; 20 percent at the Frantic Goat Campaign; 10 percent at the North Vietnam Army campaign; 10 percent at the [[Trail Campaign]] (targeting the Ho Chi Minh Trail); and 5 percent at the [[B-52 Follow-Up Programme]], which distributed surrender materials in areas immediately after B-52 bombing strikes.[^1]

Leaflets targeted at Chieu Hoi inducement addressed five principal psychological vulnerabilities identified in intelligence assessments of enemy personnel: hardship, fear of continued combat, loss of faith in victory, disillusionment with the enemy cause, and concern about families at home. The most effective single inducement was not abstract promises of amnesty or good treatment but the direct testimony of insurgents who had already surrendered, broadcast in their own voices or reproduced in leaflets bearing their personal accounts.[^1]

### Operational Use in Tintinnabulation

Chieu Hoi surrender tapes formed the second phase of [[Operation Tintinnabulation]], conducted by the [[10th Psyop Battalion]] and the [[5th Special Squadron]]. The first phase of that operation used pulsating noise from aircraft to eliminate any sense of security in target areas at night; the second phase broadcast Chieu Hoi appeals to a population already psychologically degraded by the harassment. Monthly defections attributed to the combined operation reportedly doubled from approximately 120 to approximately 380 per month.[^1]

### Research Foundation

The [[Operations Research Office]] at [[Johns Hopkins University]] studied psychological and social conditions among communist soldiers during the Korean War, and the [[Rand Corporation]]'s Viet Cong Motivation and Morale Study, conducted in the mid-1960s, examined the same conditions in Vietnam.[^2] The Rand study, which interviewed approximately 450 captured personnel through 1965, focused specifically on identifying weaknesses and vulnerabilities in Viet Cong commitment that could be exploited through psyops programs including Chieu Hoi.[^1] ORO was dissolved in June 1961 and its research program passed to the Research Analysis Corporation on September 1, 1961.[^2]

### Defection Process Scholarship

The five-phase defection model described by O'Brien drew on earlier Korean War-era work by the Operations Research Office on disaffection among communist soldiers. The model was used not only for Vietnam but as a general template in US counterinsurgency doctrine for structuring defection programs in other theaters.[^1]

### Footnotes

[^1]: Peter Watson, *War on the Mind: The Military Uses and Abuses of Psychology*. Basic Books, 1978. pp. 388-416 (Ch. 21, Ch. 22).
[^2]: U.S. Congress, Office of Technology Assessment, "A History of the Department of Defense Federally Funded Research and Development Centers," OTA-BP-ISS-157, June 1995, p. 21. https://web.archive.org/web/2016id_/https://www.princeton.edu/~ota/disk1/1995/9501/950106.PDF