History of Sino-Russian relations

Prior to the 17th century, China and Russia were on opposite ends of Siberia, which was populated by independent nomads. By about 1640 Russian settlers had traversed most of Siberia and founded settlements in the Amur River basin. From 1652 to 1689, the Qing dynasty's armies drove the Russian settlers out, but after 1689, the Qing and the Russian Empire made peace and established trade agreements.

By the mid-19th century, the Qing dynasty's economy and military lagged far behind the colonial powers. It signed unequal treaties with Western countries and Russia, through which Russia annexed the Amur basin and Vladivostok. The Russian Empire and Western powers exacted many other concessions from the Qing, such as indemnities for anti-Western riots, control over China's tariffs, and extraterritorial agreements including legal immunity for foreigners and foreign businesses. Issues that affected only Russia and China were mainly the Russian-Chinese border since Russia, unlike the Western countries, bordered China. Many Chinese people felt humiliated by the Qing's submission to foreign interests, which contributed to widespread hostility toward the Qing emperor.

The 1911 Revolution led to the establishment of the Republic of China. However, the Beiyang government, was forced to sign more unequal treaties with Western countries and Russia. In late 1917, after the beginning of the Russian Civil War, Beiyang government sided with the White Russians and sent troops to fight against the Bolsheviks. The Soviet Union, established in 1922, supported the Kuomintang and ordered the Chinese Communist Party (CCP) to enter into an alliance them in 1923. The First United Front launched the Northern Expedition, aiming to united China. In 1927, Kuomintang turned against the CCP, leading to the start of the Chinese Civil War. After the beginning of the Second Sino-Japanese War in 1937, the Soviet Union provided military help to the Republic of China, eventually launching an invasion of Manchuria in 1945, which at the time was under Japanese occupation.

After Japan was defeated in 1945, the Chinese Civil War erupted again. In 1949, with Soviet support, the CCP established the People's Republic of China, which entered into an alliance with the Soviets. After Stalin's death in 1953, Nikita Khrushchev came to power, who denounced Stalin in 1956, leading to ideological tension between the two countries to emerge. In 1961, CCP leader Mao Zedong accused the Soviet leadership of revisionism, leading to the Sino-Soviet split. Both countries competed for leadership over the global communist movement. In 1969, a brief border war between the two countries occurred. Khrushchev was replaced by Leonid Brezhnev in 1964, who abandoned many Soviet reforms criticized by Mao. However, China's anti-Soviet rhetoric intensified under the influence of the Gang of Four. Mao died in 1976, and the Gang of Four lost power in 1978. After a period of instability, Deng Xiaoping became the new leader of China. The philosophical difference between both countries lessened since China's new leadership abandoned anti-revisionism. Deng's reform and opening up did not bring an immediate end to conflict with the Soviet Union. In 1979, China invaded Vietnam, which was a Soviet ally. After Mikhail Gorbachev became the Soviet leader in 1985, the Soviet Union reduced the garrisons at the Sino–Soviet border ad in Mongolia, resumed trade, and dropped the border issue.

Rapprochement accelerated after the Soviet Union fell and was replaced by the Russian Federation in 1991. Sino–Russian relations since 1991 are currently close and cordial. Both countries maintain a strong geopolitical and regional alliance and significant levels of trade. The land border between the two nations was demarcated in 1991, and they signed the Treaty of Good-Neighborliness and Friendly Cooperation in 2001. Ties have continued to deepen after the 2022 Russian invasion of Ukraine, with Russia increasingly becoming dependent on China since it was hit with large-scale international sanctions.