when did relations between china and the soviet union begin to improve
Sino-Soviet relations Since the Sino-Soviet Treaty of Friendship resulted in the Soviet Union losing its naval bases in Port Arthur and Dalian, the issue that Stalin had to face was to find a new ice-free port as a Soviet naval base. This issue motivated Stalin's support for allowing Kim Il-Sung to launch the Korean War.[4] However, both Kim Il-Sung and Stalin did not consider that the United States would intervene into that war immediately, if at all. Kim Il-Sung could not sustain the attack against the US Army. When Kim Il-Sung required military assistance from the Soviet Union and China, Mao agreed to send Chinese troops, but asked the Soviet Air Force to provide air cover. As the two leaders distrusted each other, Stalin agreed with sending Chinese troops to Korea, but refused to provide air cover.[5] Since without the air cover from the Soviet Union, Mao once considered that China did not send troops into Korea, and Stalin at one time decided to give up the Korea Peninsula.[5] After much cogitation, Mao solely sent Chinese troops into Korea on 19 October 1950 under an extremely hard Chinese economic and military situation. This activity ultimately changed the Sino-Soviet relationship. After 12 days of Chinese troops entering the war, Stalin allowed the Soviet Air Force to provide air cover, and supported more aid to China.[5] Mao sending Chinese troops to take part in the Korean War was followed by large-scale economic and military cooperation between China and the Soviet Union, and the friendly relationship of the two countries changed from titular to virtual. In one less known example of the Sino-Soviet military cooperation, in Aprilâ€“June 1952 a group of Soviet Tupolev Tu-4 aircraft were based in Beijing to perform reconnaissance missions on American fusion bomb tests in the Pacific.[6]
Cold War By the 1970s, both sides had become interested in making accommodations in order to create a more stable and predictable international system, inaugurating a period of détente that saw Strategic Arms Limitation Talks and the US opening relations with the People's Republic of China as a strategic counterweight to the Soviet Union. Détente collapsed at the end of the decade with the beginning of the Soviet–Afghan War in 1979. The early 1980s were another period of elevated tension, with the Soviet downing of Korean Air Lines Flight 007 (1983), and the "Able Archer" NATO military exercises (1983). The United States increased diplomatic, military, and economic pressures on the Soviet Union, at a time when the communist state was already suffering from economic stagnation. In the mid-1980s, the new Soviet leader Mikhail Gorbachev introduced the liberalizing reforms of perestroika ("reorganization", 1987) and glasnost ("openness", c. 1985) and ended Soviet involvement in Afghanistan. Pressures for national independence grew stronger in Eastern Europe, especially Poland. Gorbachev meanwhile refused to use Soviet troops to bolster the faltering Warsaw Pact regimes as had occurred in the past. The result in 1989 was a wave of revolutions that peacefully (with the exception of the Romanian Revolution) overthrew all of the communist regimes of Central and Eastern Europe. The Communist Party of the Soviet Union itself lost control and was banned following an abortive coup attempt in August 1991. This in turn led to the formal dissolution of the USSR in December 1991 and the collapse of communist regimes in other countries such as Mongolia, Cambodia and South Yemen. The United States remained as the world's only superpower.