Cambodian–Vietnamese War
1978–1989 interstate war
The Cambodian–Vietnamese War was an armed conflict from 1978 to 1989 between Democratic Kampuchea and the Socialist Republic of Vietnam, and their respective allies. It began in December 1978, with a Vietnamese invasion of Cambodia which toppled the Khmer Rouge regime and ended in 1989 with the withdrawal of Vietnamese forces from Cambodia. This Cold War conflict was part of the Third Indochina War and Sino-Soviet split with the Soviet Union supporting Vietnam and China supporting Kampuchea.
Despite both being communist, the alliance between the Communist Party of Vietnam and the Khmer Rouge broke down after both defeated Vietnamese and Cambodian anti-communist regimes respectively in the Second Indochina War. As a result, the war was preceded by years of conflict between Vietnam and the Khmer Rouge, led by Pol Pot, when the Khmer Rouge-ruled Democratic Kampuchea repeatedly invaded Vietnam, including massacres by the Khmer Rouge, notably the Ba Chúc massacre of over 3,000 Vietnamese civilians in April 1978. On 21 December 1978, the Vietnamese launched a limited offensive towards the town of Kratie. On 23 December 1978, 10 out of 19 divisions of the Khmer Rouge's Kampuchea Revolutionary Army opened fire along the border with Vietnam with the goal of invading the southwestern border provinces of Đồng Tháp, An Giang and Kiên Giang. On 25 December 1978, Vietnam supported Cambodian dissidents in exile and launched a full-scale invasion of Kampuchea, occupying the country in two weeks, capturing the capital Phnom Penh, and removing the Khmer Rouge government of the Communist Party of Kampuchea from power. In doing so, Vietnam put an ultimate stop to the Cambodian genocide which had killed between 1.2 and 2.8 million people or between 13 and 30 percent of the country's population since 1975. However, the Khmer Rouge regime maintained its membership in the United Nations and the war isolated Vietnam from the international community except the Eastern Bloc.
This brief starts where responsible research should: with the source description of “Cambodian–Vietnamese War” as 1978–1989 interstate war. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the history & society register because the source frames it as 1978–1989 interstate war. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Chronology, provenance and viewpoint should be read together before a broad social or political interpretation is accepted. The source revision retrieved here is dated Sep 26, 2026. The linked authority identifier is Q635533. The Library of Congress control number is sh85019096. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1978, 1989 and 1975.
Official terminology may obscure informal participation, dissent or communities documented only indirectly. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
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This entry incorporates text from “Cambodian–Vietnamese War” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.