The border between China and Vietnam consists of a terrestrial border in southern China and northern Vietnam, and a maritime border in Gulf of Tonkin and South China Sea. While disputes over the terrestrial border have been largely settled with the signing of a land boundary treaty between the two countries, the maritime border is currently been undefined due to disputes over the ownership of islands, territorial waters, including over the Spratly and Paracel Islands, and territorial waters.
Land border
The terrestrial border stretches about 1,444 km from the China-Laos-Vietnam tripoint on the peak of the Shiceng Dashan peak in the west to the mouth of the Beilun/Ka Long River near the Chinese city of Dongxing and the Vietnamese city ofMóng Cái in the east. The border passes through isolated mountainous areas inhabited by ethnic minorities of both China and Vietnam. In several areas, the land border between the two countries runs along rivers. In particular, the border follows the Red River on its section from the mouth of the Longbao River to the mouth of the Nanxi River. The lower sections of the Longbao and Nanxi are border rivers as well.
History
An aftermath of the Lý–Song War that still exists today resulted from an agreement that was negotiated by both sides that fixed the two country's borders the resulting line of demarcation exists largely unmodified to the present day.
The Treaty of Tientsin, after the end of the Sino-French War, provided for the demarcation of the border between China and Vietnam. Article 3 of the treaty provided for the appointment of a Sino-French commission to demarcate the border between Tonkin and China, which largely forms today's China–Vietnam border. China's commissioners were Chou Te-jun, Hung Lu-ssu and Ch'ing Teng-ch'eng. The French commission was led by M. Bourcier Saint-Chaffray, and its members included M. Scherzer, the French consul in Canton, Dr Paul Neis, a noted Indochina explorer, Lieutenant-Colonel Tisseyre, Captain Bouinais, and M. Pallu de la Barrière. In preparation for the commission's work General de Courcy despatched French troops to occupy Lạng Sơn, That Khe and other border towns in October 1885. Demarcation work began in late 1885 and was completed in 1887. The French rejected Chinese claims to the Vietnamese town of Dong Dang, close to the Guangxi border and the site of a French victory during the Sino-French War, but agreed that the Pak-lung peninsula on the western border of Guangdong province should be awarded to China. A dispute over two areas on the border between Yunnan province and Tonkin was settled by the award of Meng-suo and Meng-lai to Vietnam and the transfer of a large tract of fertile arable land between Ma-pai-kuan and Nan-tan-shan to China. An agreement confirming the new border between Vietnam and China was signed in Peking on 26 June 1887 by French and Chinese representatives.
Boundary Conventions of 1887 and 1895
The 1887 Convention, signed on 26 June, and 1895 Additional Convention between the French Government on behalf of Vietnam and the Qing Dynasty were considered the first international legal documents determining the border between Vietnam and China. The borderline that was jointly defined by the French and the Qing Dynasty largely followed the borderline already formed through history. The conventions also resulted in 341 simple border markers from Mong Cai to the Laos-China border being erected. The border demarcation between the French and the Qing Dynasty was described as being carried out under "incomplete technical and practical conditions and incomplete and unclear and inaccurate texts and maps of many border sections." The border markers were erected not based on a coordinate grid and many suffered damage, were lost through time or removed. Many of the original maps also no longer existed and migration of populations took place not in accordance with the de jure borderline. All these factors posed difficulties to border management.
During the Chinese Civil War, China used the border near Vietnam as a refueling station while also giving aid to the Vietnamese who were fighting the French in the First Indochina War.
Border crossings and trade points
China and Vietnam signed an agreement on border trade in 1991. In 1992, 21 border trade points were opened of which four also served as border crossings. ;List of border crossings and trade points The major border crossings are highlighted in bold. From west to east:
