Why did China and Vietnam go to war in 1979? What factors have affected their relationship?

China invaded and colonized the northern part of Vietnam for more than 1,000 years, before finally being driven out by fierce rebellions. Subsequent attempts to invade the country – Dai Viet – under the Mongol Yuan Dynasty were resisted at the famous Battles of Bach Dang.

The Dai Viet state strengthened, based on the fertile rice-growing land in the Red (Hong) River Delta region and extended southwards, conquering and absorbing the land of the Chams, who occupied what is now the southern half of Vietnam. In the centuries that have followed, the populous Vietnamese have expanded their territory, controversially taking the land of the Mekong Delta from the less numerous Khmer people.

During the period of French colonization, from the second half of the nineteenth century to the defeat at Dien Bien Phu in 1954, Indochina (i.e., Vietnam, Laos and Cambodia) was for the first time in history conceived of as a single territorial unit to be administered as one country. This idea resurfaced during and after the Communist Revolutions which drove out the American military, which had replaced the French in trying to impose a form of political regime on the people of the region. It contributed to the subsequent tendency in the Vietnamese Communist Party leadership endeavouring to export its ideology and methods to its ‘younger brother’ partners in Laos and Cambodia. This has included training hundreds or thousands of students and government officials in Vietnam and provided all kinds of technical support and advice in addition.

Throughout these struggles, the Chinese state and people had supported the Vietnamese, in particular, out of a sense of fraternal comradeship and to resist foreign aggressors. However, while the Vietnamese of course welcomed all forms of assistance, ranging from weapons and military supplies to thousands of workers helping to keep the roads open, they did not feel that it made them beholden to the Chinese. The memory of past injustices weighs heavily upon the societies of the world. The Vietnamese state wanted to assert itself and, crucially, were willing to accept more Soviet assistance to obtain its goals. The Chinese, meanwhile, were outraged by what they considered to be an act almost of betrayal and certainly of ingratitude. During the mid to late 1970s, numerous border incidents across the Indochina region threatened to lead to major wars between any or all of the countries involved. The Vietnamese poured oil onto the fire by victimizing the estimated 200,000 Chinese in the country, deporting many of them. It is not surprising, in hindsight, that the war between Vietnam and China should have broken out when it did. It is fortunate that the Chinese maintained so much restraint over their campaign, preventing the war from escalating even more than it did.