China–Vietnam relations

Relations between Vietnam and China (Chinese: 中越关系, pinyin: Zhōng Yuè Guān Xì; Vietnamese: Quan hệ Việt–Trung) have been extensive for millennia, with Northern Vietnam especially under heavy Sinosphere influence during historical times. Despite their Sinospheric and socialist background, centuries of conquest by modern China's imperial predecessor as well as modern-day tensions have made relations wary. The modern relationship has been marked with extensive economic, political and cultural ties, as well as territorial disputes in the South China Sea.

China and Vietnam have lengthy historical connections, including nearly a thousand years during which Vietnam was a dependency of China. Vietnam emerged from the disintegration of China's Tang dynasty in the 900s. Subsequently, China supported the Trần dynasty while the Ming dynasty established a tributary relationship with Vietnam. In 1884, after Chinese defeat in the Sino-French War, Vietnam under the Nguyễn dynasty became a protectorate of France, marking the end of formal Chinese influence on Vietnam. During the Cold War, the People's Republic of China (PRC) ruled by the Chinese Communist Party (CCP) assisted North Vietnam and the Communist Party of Vietnam (CPV) during the Vietnam War whilst the Taiwan-based Republic of China (ROC) was allied with South Vietnam.

Following the fall of Saigon in 1975 and the subsequent Vietnamese reunification as the Socialist Republic in 1976, relations between the two countries started to deteriorate. Vietnam ousted the Khmer Rouge, a party that China propped up which had become genocidal, from power in Cambodia. China invaded Vietnam in February 1979, beginning the Sino-Vietnamese War. China perceived Vietnam's domination over Indochina from Vietnam's historical legacy (emperor Minh Mạng) whilst Vietnam desired Vietnamese-friendly neighbors (Laos and Cambodia) on its immediate western borders. Cross-border raids and skirmishes ensued, in which China and Vietnam had a series of border and naval clashes from 1979 to 1990. The two countries officially normalized diplomatic ties in 1991.

China and Vietnam share a 1,281 kilometres (796 miles) border. The two countries remain in dispute over political and territorial issues in the South China Sea. Since the normalization of diplomatic ties, both sides have since worked to improve their diplomatic and economic relations. The two countries have been striving for restraint as well as present and future stability. The two countries signed a comprehensive strategic partnership in 2008. China and Vietnam maintain extensive economic ties, with the Vietnamese economy becoming increasingly connected with China's. As two ruling communist parties of socialist states, the CCP and CPV maintain close political and ideological ties.