Fighting broke out between Soviet and Chinese units on on Damansky/Zhenbao Island on March 2, 1969. Following this incident, sensationalist news reports by the media stirred up the general population in both countries. On March 3, 1969 in Beijing, large protests were held outside the Soviet Embassy, and Soviet diplomatic personnel were harassed. In the Soviet Union, demonstrations were held in Khabarovsk and Vladivostok. In Moscow, angry crowds hurled stones, ink bottles, and paint at the Chinese Embassy.
On March 11, 1969 in Beijing, demonstrators besieged the Soviet Embassy in protest for the attack on the Chinese Embassy. Then when Soviet media reported that captured Russian soldiers during the Damansky/Zhenbao incident had been tortured and executed, and their bodies mutilated, large demonstrations consisting of 100,000 people broke out in Moscow. Other mass assemblies also occurred in other Russian cities.
On March 15, 1969, a second (and larger) clash broke out in Damansky/Zhenbao Island, where both sides sent a force of regimental strength, or some 2,000-3,000 troops. The Chinese claimed that the Soviets fielded one motorized infantry battalion, one tank battalion, and four heavy-artillery battalions, or a total of over 50 tanks and armored vehicles, and scores of artillery pieces. The two sides again claimed victory in the 10-hour battle, and also accused the other side of firing the first shots. Both sides suffered heavy casualties.
(Taken from Sino-Soviet Border Conflict – Wars of the 20th Century – Twenty Wars in Asia)
Background Historically, the communist parties of Russia and China had not had close ties, and were even hostile to each other. During the early years of the Chinese Communist Party, in 1923, the Soviet government under Vladimir Lenin encouraged the Chinese communists to join the non-communist Kuomintang (Chinese Nationalists). Then in World War II, Stalin urged Mao to form an alliance with Chiang Kai-shek to fight the Japanese. In the 1930s, Mao began to view traditional Marxism, like that applied in the Soviet Union, as relevant only in the industrialized countries, and not consistent with China’s agricultural society. Mao soon developed a new branch of Marxism called Maoism, which stated that in agricultural societies, the revolutionary struggle should be led by the peasants.
In September 1963-July 1964, Mao published a series of papers condemning Khrushchev and Soviet policies. In October 1964, Leonid Brezhnev succeeded as the new leader of the Soviet Union, and overturned some of the liberal reforms of his predecessor, although he generally continued to implement party policies. Brezhnev adopted a hard-line stance on the West, which did not lead to improved Sino-Soviet relations. Instead, ties between the two communist countries continued to decline. By 1963, the Sino-Soviet split involved the long-standing territorial dispute along the two countries’ poorly defined 4,380-kilometer shared border. In July 1964, Mao stated that the territory of the Soviet Union was excessive, and that Soviet regions of Lake Baikal, Vladivostok, Khabarovsk, and Kamchatka formerly belonged to China. Mao then said that China had “not yet presented our bill for this list” to the Soviet Union.
China then declared that two 19th century treaties with the Soviet Union, the Treaty of Aigun (1858) and the Convention of Peking (1860), were “unequal treaties”, in that the then ruling powerful Russian Empire had forced the war-weakened Chinese Qing Dynasty to cede one million square kilometers of territory in Manchuria and Siberia to Russia. Mao’s government also stated that through other “unequal treaties” which the Qing court was forced to sign in the 19th century, China lost some 500,000 square kilometers of land in its western border, lands which now are part of the Soviet Union.
The Chinese government soon made the clarification that by bringing up the matter of “unequal treaties” with the Soviet Union, China did not seek to reclaim these territories, but that it wanted the Soviet Union to acknowledge that the treaties indeed were unjust, and that the two sides must negotiate a final border agreement on the basis of present-day boundaries. In this respect, for China, the disputed territory amounted to only 35,000 square kilometers along the common border. And of this figure, 34,000 square kilometers were located in the western side bordering the Soviet Socialist Republics of Kazakhstan, Kyrgyzstan, and Tajikistan. Another 1,000 square kilometers were located along the eastern side running along the length of three rivers: the Argun, Amur, and Ussuri (Figure 20).
Both the Treaty of Aigun and the Convention of Peking, which codified the border along the eastern side, stipulated that the Sino-Russian border was located on the Chinese side running the whole length of the three rivers, thus giving the Russians full sovereignty along these rivers, including the many hundreds of islands located therein. China wanted to negotiate a readjustment of this river border, and proposed that the new border line be placed at the midpoint of the rivers. The Soviet Union rejected any readjustments, stating that the existing treaties had already fixed the border.
Furthermore, the Soviet Union denied that the 19th century treaties were “unequal treaties”, and countered by stating that the Chinese rulers themselves were territorially ambitious at that time. The Soviets also stated that in recently signed land treaties between China and the Soviet Union, Mao’s government had not brought up the matter of the earlier “unequal treaties” in these areas, and thus constituted a tacit acknowledgment of Soviet sovereignty of these areas. In February 1964, the two sides held border talks, which collapsed later that year when Mao raised new criticisms against the Soviet government.
Both sides now increased their forces at the border, raising tensions. The Soviet government also strengthened its relations with Mongolia (a socialist client state of the Soviet Union). In January 1966, the two countries signed a military alliance that allowed Soviet troops to deploy in Mongolia to help defend the country against a possible Chinese attack.
In 1966, Mao launched the Cultural Revolution, where he purged his political rivals and took full control of the Chinese Communist Party. But the Cultural Revolution brought widespread turmoil in China, and also exacerbated the ideological clash between China and the Soviet Union, increasing tensions between them.
In August 1968, the Soviet Union invaded Czechoslovakia, and overthrew the socialist government there that had tried to implement liberal reforms. Mao saw this aggression as one which the Soviets could potentially undertake against China. By the mid-1960s, the Soviet-Chinese border was heavily militarized, and hundreds of skirmishes took place, which increased in frequency in 1968 in the highly volatile eastern border region. Soviet soldiers used physical force to remove Chinese fishermen and worker groups, as well as Chinese military patrols, which had entered the river islands. In January 1968, China filed a diplomatic protest when Soviet troops attacked and killed Chinese workers in Qiliqin Island.