What is the Jeju 4·3 Incident?
Jeju 4·3 (pronounced “four-three”) refers to a period of political violence and mass civilian victimization on Jeju Island, Korea, that began in the aftermath of Japan’s surrender in 1945 and unfolded amid the early Cold War division of the Korean Peninsula. In Korean public life it is often called the “Jeju 4·3 Incident,” the “Jeju Uprising,” or the “Jeju Uprising and Massacre.”
Under Korean law, “the Jeju 4·3 Incident” is defined as the incident in which civilians were sacrificed during armed conflict and suppression operations from March 1, 1947 through September 21, 1954.
Why it is called “4·3”
The name comes from April 3, 1948, when armed attacks began and the conflict entered a decisive phase. Over time, “4·3” became shorthand for the broader multi-year cycle of violence, not a single-day event.
A brief timeline
March 1, 1947: A rally on Jeju escalates after police fire on civilians, a moment many accounts identify as a key trigger for intensified conflict. (Korea Policy Institute)
April 3, 1948: Armed resistance and state repression expand.
Late 1948 to early 1949: Large-scale “scorched earth” style operations produce the highest civilian toll, alongside detention, torture, village destruction, and summary executions documented in multiple historical studies. (Asia-Pacific Journal: Japan Focus+1)
September 21, 1954: The period is commonly marked as ending when restrictions tied to the conflict are lifted.
What happened, in plain terms
Jeju 4·3 was not simply one “day of violence.” It was a multi-year process in which political polarization, counterinsurgency, and state security measures repeatedly collided with civilian life. Communities were subjected to sweeping suspicion, forced displacement, detention, and lethal violence. The result was not only the loss of life, but also the long-term breakdown of trust within families, villages, and public institutions.
Many American readers instinctively picture “massacre” as distant killing by artillery or aerial bombardment. Jeju 4·3 is often remembered differently: as violence carried out at close range through policing, raids, detention, interrogation, and executions, intertwined with the destruction of everyday social relations.
How many people were harmed
Numbers vary depending on definitions and documentation methods, and that variance is itself part of why rigorous historical work matters.
A widely cited estimate is about 30,000 deaths, often described as nearly one-tenth of the island’s population at the time, alongside the destruction of many villages and homes. (heritage.arch.cam.ac.uk)
Separate from estimates, “registered” or “identified” victim counts appear in official and institutional records and have changed over time as documentation has expanded. (For example, one public-facing summary reports registered victims in the mid–14,000 range as of a recent reporting period, while also noting higher estimated totals.)
Why scholars see Jeju 4·3 as a Cold War turning point
Jeju 4·3 is frequently analyzed as an early flashpoint of Cold War governance and security policy in Northeast Asia. One scholarly synthesis describes Jeju 4·3 as a watershed for understanding the development of the Korean War, linking the episode to the broader architecture of emergency powers, counterinsurgency, and mass political violence that intensified across 1948–1953. (Asia-Pacific Journal: Japan Focus)
You may also encounter strong formulations in the literature, including claims that Jeju 4·3 was among the earliest large-scale civilian massacres in post–World War II Asia. Some peer-reviewed writing uses “first” language, but the more careful takeaway is this: Jeju 4·3 sits near the beginning of a postwar regional pattern in which anti-communist state-building, occupation-era governance, and internal security campaigns produced catastrophic civilian harm.
The U.S. connection, and why it belongs in an American conversation
Jeju 4·3 began during the period of the United States Army Military Government in Korea (USAMGIK), when the U.S. functioned as the occupying authority in southern Korea after 1945. U.S. government historical documentation notes that the United States terminated Military Government on August 15, 1948 and then began transferring governmental functions to the newly inaugurated Republic of Korea. (Office of the Historian)
That timing matters because Jeju 4·3 intensified across the boundary between occupation governance and the early Republic’s security apparatus. The question is not a simplistic binary of “the U.S. did everything” versus “the U.S. had nothing to do with it.” The serious question is procedural and evidentiary:
What did U.S. authorities know, and when?
What policy priorities shaped security practices under occupation and after transfer of authority?
What advisory, training, or operational relationships existed, and how did they influence outcomes?
Even in Korean policy analysis, Jeju 4·3 is explicitly discussed as an episode that began under U.S. military government, and U.S. responsibility and apology are repeatedly raised as unresolved issues in the broader landscape of Korea’s transitional justice.
Why we built this resource in the United States
Most Americans have never heard of Jeju 4·3. That absence is not neutral. It shapes which histories are legible, which losses are recognized, and which standards of human rights and accountability are applied consistently across alliances.
Scholarly writing on reparative justice for Jeju 4·3 emphasizes how limited international awareness remains and how reconciliation efforts can stall when accountability is treated as “finished business” rather than an ongoing process. (Southwestern Law School)
Walden Korea and the Jeju 4·3 Memorial and Victims’ Families Association in the U.S. created this site for three practical reasons:
Public education in English. We provide reliable, documented entry points for people encountering Jeju 4·3 for the first time.
A procedural approach to truth and accountability. We focus on records, verification, and explainable claims, not partisan spectacle.
Human dignity and trauma awareness. Jeju 4·3 is not only “history.” It is intergenerational trauma carried by survivors and families, including within diaspora communities in the United States.
Our goal is not to convert grief into political theater. Our goal is to support a credible historical record, insist on human-rights standards worthy of democratic societies, and create the conditions in which acknowledgment, education, and prevention become possible.
References and further reading
Walden Korea Journal, Issue 1- Walden Korea Publication Page
Jeju 4·3 Peace Foundation (Official, English PDF Guide) - A Guide to the History of the Jeju 4·3 Incident
Special Law translation (definition and dates): “The Special Law for Truth Investigation about the Jeju 4·3 Incident and Honoring Victims,” excerpted in The Jeju 4.3 Incident Investigation Report (download page). cdm21069.contentdm.oclc.org
U.S. Military Government termination and transfer: U.S. Department of State, Office of the Historian, Foreign Relations of the United States (FRUS), noting termination of Military Government on Aug. 15, 1948 and transfer of functions. Office of the Historian
Cold War and Korean War “watershed” framing: Su-kyoung Hwang, “South Korea, the United States and Emergency Powers During the Korean Conflict,” Asia-Pacific Journal: Japan Focus (2014). Asia-Pacific Journal: Japan Focus
Scale estimates and Peace Foundation-referenced figures: Cambridge Heritage Research Centre, “Commemorating South Korea’s Cheju April 3rd Incident” (includes death-toll estimates and cites the Jeju 4.3 Peace Foundation as a source for victim-registration figures). heritage.arch.cam.ac.uk
Transitional justice and the role of Jeju 4.3 Peace Foundation investigations: East Asia Institute, discussion of Jeju 4·3 within Korea’s transitional justice landscape, including continued investigations by the Jeju 4.3 Peace Foundation and the recurring question of U.S. responsibility. eai.or.kr
Reparative justice and limited international awareness: Eric K. Yamamoto, Miyoko Pettit & Sara Lee, “The 2018 Reopening of the Jeju 4.3 Mass Convictions,” (PDF), discussing ongoing reconciliation needs and the lack of broader awareness. Southwestern Law School
Additional background (accessible overview that explicitly situates Jeju 4·3 under USAMGIK): Korea Policy Institute article, “Early Cold War Genocide: the Jeju 4.3 Massacre and U.S. Responsibility” (2020). Korea Policy Institute