Cambodia–Vietnam relations refer to bilateral relations between the Cambodia and the Vietnam. Both countries share a land border and share historical links as being part of the French colonial empire. Both countries are members of ASEAN.
Both the Vietnamese and Khmer languages are distant cousins which split off from the Mon–Khmer family over a thousand years ago. However, Vietnamese society was heavily Sinicized and Khmer society Indianized, and the countries did not share a common border. Much of Vietnam's southward territorial expansion started by the Ly and expanded by the Tran dynasty from the 14th century onward came at the expense Champa which became an increasingly compressed polity. By the 17th century the Vietnamese court encouraged settlers to push into Khmer territories, eventually wresting the Mekong Delta from the Cambodian court. Today, Cambodia shares a 1,137 kilometres long border with Vietnam in the east and southeast.
The 16th and 17th centuries marked the height of the Kinh people's (ethnic Vietnamese) penetration into the southern Mekong Delta, displacing the Khmers. Military campaigns by Nguyen Phuoc Yen opened up more Khmer land for Vietnamese settlement which was followed by Nguyen Phuoc Lam's consolidation of Vietnamese control over the Prey Nokor (later Saigon) region in 1674. Both Mesa (modern Mỹ Tho) and Longhor (modern Vĩnh Long) fell to the Vietnamese by 1732. Nguyen Thien Chinh's and Nguyen Cu Trinh's armies in the 1750s took control of Mekong estuaries, basically cutting off the Cambodian's riverine access to the sea. The Vietnamese presence was bolstered following the Manchu conquest of China (1618-1683) when groups of Ming loyalist refugees came to the region seeking the protection of the Nguyễn lords. Those led by Mạc Cửu (1655-1735) helped settle Hà Tiên while others flocked to Bien Hoa and My Tho, pushing out the Khmers. By 1775, the Cambodian court had ceded the areas of Praah-Trapeng (Trà Vinh), Srok Trang (Sóc Trăng), and Meat Chruk (An Giang) to the Vietnamese without bloodshed.
With the rise of the Nguyễn Dynasty in the early 19th century, southern Vietnam came under tighter control of the Court. The Vietnamese emperor Minh Mạng (1820-41) took the paternalistic views that the Khmers were backwards and ordered his general Trương Minh Giảng to "civilize" the "barbarian" Cambodians. Cambodia itself was brought under Vietnamese control with the occupation of Phnom Penh. Truong reported back: "we have decided that Cambodian officials only know how to bribe and be bribed. Offices are sold. Nobody carries out orders; everyone works for his own account". A policy of cultural Vietnamization ("Nhat Thi Dong Nhan") was imposed, forcing Khmers to adopt Vietnamese attire, names and language. State-encouraged Vietnamese settlement in Phnom Penh ("Tran Tay") accelerated, and Vietnamese occupying forces spirited away native Cambodian leaders like Ang Mey to inland Vietnam, in order to weaken Khmer resistance. However, Khmer uprisings in southern Vietnam from 1840 to 1845 made this policy of direct rule inconvenient and expensive for the Vietnamese court, which opted to keep Cambodia as a tributary state after the death of Minh Mang.
After the Siamese–Vietnamese Wars, first in the 1830s and then a decade later, Cambodia became a vassal state under Vietnam and Siam, with the country becoming culturally and administratively Vietnamized. In 1863, the Thai-raised King Norodom of Cambodia (reign 1860-1904) signed a treaty with the French Empire, granting them mineral exploration rights if they would secure the country against Thai and Vietnamese attack. However, during the colonial rule of French Indochina, which would later come to include Vietnam, French authorities imported Vietnamese laborers to Cambodia, where the growing minority came to dominate businesses and water resources in the country. In the First Indochina War for independence, some Cambodians, including King Norodom Sihanouk, fought against Viet Minh forces because they feared Vietnamese colonial domination.
After independence, the Kingdom of Cambodia maintained diplomatic relations with both North Vietnam and South Vietnam. However, the Viet Cong used Cambodia as a base to fight the Vietnam War, and the Southern Ngo Dinh Diem administration pursued political opponents even into Cambodian territory. In the Bangkok Plot, the Diem administration attempted to overthrow Sinahouk's government and replace it with a right-wing pro-South regime. The United States Army also bombed Cambodian territory in pursuit of Vietnamese communists, resulting in up to 150,000 Cambodian deaths. Despite attempts to negotiate with "whichever [Vietnamese state] will turn out to be most reasonable in... [demarcating] our common frontiers", Sinahouk failed to get a hearing from a Vietnamese government about latent territorial disputes in Cochinchina and especially Koh Tral (Phú Quốc) island. The king himself was accused of accommodating Vietnamese military bases in Cambodia, and widespread anti-Vietnamese riots culminated in the Cambodian coup of 1970. Referring mainly to Viet Cong operating in the border region, the new Cambodian president Lon Nol declared: "According to Buddhist religion, there must be a war. A war against the Vietnamese Communists who consider religion their enemy". However, Nol also attempted to expel the 40,000 South Vietnamese troops whose presence in Cambodia outnumbered Cambodia's own military forces. The Khmer Rouge opposition came to power in Cambodia in 1975, shortly before the Fall of Saigon to Northern forces.
In 1979, as a result of the Cambodian–Vietnamese War, Vietnam overthrew the Khmer Rouge and occupied Cambodia, establishing the puppet People's Republic of Kampuchea. Vietnamese state media published propaganda that justified the occupation with reference to Vietnamese history. For example, one book stated: "The Vietnamese have had cultural ties to the people of Kampuchea since at least the Dong Son era [850 B.C. to A.D. 280]. These ties have never stopped growing throughout history. [Therefore], the immigration of Kampucheans into Southern Vietnam and the settlement of Vietnamese in Kampuchea are natural manifestations of these ties."
Vietnamese occupying soldiers and journalists also discovered evidence of the Khmer Rouge's abuses, such as Tuol Sleng prison facility, and widely publicized them. The United States initially suspected the Vietnamese of falsifying this evidence, and warned them not to continue their army's march to Thailand, which they in fact did, in hot pursuit of the Khmer Rouge resistance.
In 2005, Vietnam and Cambodia signed a supplementary treaty to the original 1985 Treaty on Delimitation of National Boundaries, which Cambodia has deemed unacceptable. As a result, Vietnam has made several claims to Cambodian land based on the treaty that raised allegations of Vietnamese encroachment. In a statement made by a government minister of the former French Indochina colonial administration, Cambodia would have to give up two of its villages to Vietnam in return for keeping two villages that was deemed Cambodian territory according to the 1985 treaty, Thlok Trach and Anlung Chrey. It is not known which two villages Cambodia would have to give up. To resolve the dispute, in 2011, the Cambodian government announced it would speed up the demarcation process with Vietnam. On June 24, 2012, Vietnam and Cambodia celebrated the demarcation of the last marker on their shared border, marker 314. Prime Ministers Nguyen Tan Dung of Vietnam and Hun Sen of Cambodia personally attended the celebration to unveil the new marker and reaffirmed the two countries' cooperation and friendship.
Since the 1990s, relations between both nations have begun to improve. Both Vietnam and Cambodia are members of multilateral regional organizations such as ASEAN and the Mekong-Ganga Cooperation. Both nations have opened and developed cross-border trade and sought to relax visa regulations to that end. Both governments have set official targets of increasing bilateral trade by 27% to USD 2.3 billion by 2010 and to USD 6.5 billion by 2015. Viet Nam exported USD 1.2 billion worth of goods to Cambodia in 2007. While Cambodia is only the 16th largest importer of Vietnamese goods, Vietnam is Cambodia's third-largest export market.
- Thu-Hương Nguyễn-Võ (1992). Khmer-Viet relations and the third Indochina conflict. McFarland. pp. 1–2, 4–5, 9–15.
- "Viet Nam-Cambodia trade set to increase 27%". Vietnam Business News. 2008-01-18. Retrieved 2008-06-11.
- Brinkley, Joel (2011). Cambodia's Curse: The Modern History of a Troubled Land. PublicAffairs. pp. 22–23, 25, 55–56.
- Pouvatchy, Joseph R. (April 1986). "Cambodian-Vietnamese Relations". Asian Survey 26 (4): 440–451. doi:10.1525/as.1986.26.4.01p03736.
- Kiernan, B. How Pol Pot Came to Power
- "Cambodia to cede two villages to Vietnam". The Phnom Penh Post. 2012-06-18. Retrieved 2012-06-27.
- "Key Viet Nam-Cambodia border marker inaugurated". Việt Nam News. 2012-06-25. Retrieved 2012-06-27.
- "Cambodia, Viet Nam target $2.3 billion in bilateral trade by 2010". Vietnam News. 2008-01-21. Retrieved 2008-06-11.