The bilateral relations between the Kingdom of Cambodia and the People's Republic of China have strengthened considerably after the end of the Cambodian–Vietnamese War, during which China had supported the Khmer Rouge against Vietnam.
History
Although the countries share no common border, China has had a historic cultural and commercial relationship with Cambodia. The 950,000 Chinese in Cambodia constitute 3-5% of Cambodia's population, and although they were discriminated against by the Khmer Rouge and the Vietnamese, they have re-emerged as a prominent business community.
The first contacts between China and the Khmer Empire of Cambodia occurred in the Tang period, and for centuries onward the two countries shared a strong trading relationship. A Chola-Song-Khmer trade axis dominated trade in the east for much of the 11th and 12th centuries. Yuan Chinese accounts of the Cambodian kingdom proved to be crucial to uncovering the history of the region. Cambodia maintained relations with Ming China as early as 1421 AD during the final years of the Khmer Empire when Ponhea Yat dispatched a minister to establish formal diplomatic ties. China has used Cambodia as a counterweight to the dominating influence of Vietnam. In the mid-20th century, Communist China supported the Maoist Khmer Rouge against Lon Nol's regime, who Nationalist China had ties with, during the Cambodian Civil War and then its takeover of Cambodia in 1975. Also, Mao Zedong had fostered good relations with Prince Norodom Sihanouk, who also fought against Lon Nol and backed the Khmer Rouge. When Vietnamese military invaded Cambodia in 1978, China provided extensive political and military support for the Khmer Rouge. In 1979, the Chinese People's Liberation Army waged a brief border war against Vietnam, partly to threaten it into pulling out of Cambodia. The Paris Peace Conference on Cambodia, from July 1989 to October 1991, resolved Cambodia–China relations and contributed to reintegrating China into major power multilateral negotiations. After Vietnam's withdrawal from Cambodia and then the 1993 UN-sponsored elections recognized and supported the new democratic government.
Since 1997, China began developing closer relations with the regime of Cambodian Prime Minister Hun Sen, once a pro-Vietnamese leader and a defector from the Khmer Rouge during Vietnam's occupation of Cambodia. Although initially backing Hun Sen's political opponent Prince Norodom Ranariddh and his FUNCINPEC, China was disenchanted with Ranariddh's efforts to build a closer relationship with Taiwan, which is claimed by China. Facing international isolation after the 1997 coup that brought him to power, Hun Sen cultivated close ties with China, which opposed efforts by Western countries to impose economic sanctions on Cambodia. China's close ties with Cambodia have also served to gain leverage against Vietnamese influence in the region.
In June 2020, Cambodia was one of 53 countries that backed the Hong Kong national security law at the United Nations.
Chinese assistance
During the visit of Chinese Premier Wen Jiabao between April 7-April 8, 2006 both nations signed several bilateral agreements and a treaty of "Comprehensive Partnership of Cooperation." China diversified its aid and investments in Cambodia and promised to provide US$600 million in loans and grants. China has canceled much of Cambodia's debt and granted a fresh loan of US$12.4 million for the construction of the building housing the Cambodian government's council of ministers and the restoration of the Angkor Wat temple and heritage site. About $200 million has been earmarked as a low-interest loan for the construction of bridges spanning the Mekong and Tonle Sap rivers. China has cultivated strong ties with Cambodia, gaining access to its sea ports that can allow China to exploit oil reserves in the Gulf of Tonkin. During the visit, Cambodian Prime Minister Hun Sen described China as Cambodia's "most trustworthy friend."
China has also cultivated military ties. In the aftermath of the 1997 coup, China provided US$2.8 million in military aid and has since supplied wide range of military equipment, training of military and police cadre and naval vessels to combat drug trafficking and piracy. China has also funded Chinese language schools in Cambodia. Immigration of Chinese workers to Cambodia has also stepped up in recent years and is estimated between 50,000 and 300,000.
Within ASEAN, Cambodia is often supportive of China.