China–Vietnam relations

Relations between Vietnam and China (Chinese: 中越关系, pinyin: Zhōng-Yuè Guān Xì; Vietnamese: Quan hệ Việt–Trung) had been extensive for a couple of 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 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 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 1979, beginning the Sino-Vietnamese War. China perceived Vietnam's domination over Indochina from Vietnam's historical legacy (Minh Mang) whilst Vietnam desired Vietnamese-friendly neighbors (Laos and Cambodia) bordering its immediate western borders.

Cross-border raids and skirmishes ensued, in which China and Vietnam fought a prolonged border war from 1979 to 1990. The two countries officially normalized diplomatic ties in 1991. Although both sides have since worked to improve their diplomatic and economic ties, the two countries remain in dispute over political and territorial issues in the South China Sea (or East Sea). China and Vietnam share a 1,281 kilometres (796 mi) border. In 2014, a survey conducted by the Pew Research Center showed 84% of Vietnamese were concerned that disputes relating to the South China Sea could lead to military conflict. However, the two countries have been striving for restraint as well as present and future stability. The two countries' political parties, although faced with a number of concerns, have since maintained ideological ties.