In the 1950s, the Soviet Union and China were close allies united by communist ideology[6][9]. However, their relationship deteriorated sharply in the late 1950s and 1960s due to ideological differences and disputes over Soviet policies of de-Stalinization and peaceful coexistence with the West[7][9]. The Sino-Soviet split culminated in 1960[11]. In the late 1960s, Sino-Soviet relations worsened to the point of possible military conflict, leading China to conclude the Soviets posed a greater threat than the U.S.[1]. This spurred China's opening to the U.S. in the 1970s in what seemed like a united front against the Soviets[6][9]. Ties remained strained through the 1970s, stabilizing but still with high military confrontation[9]. Mikhail Gorbachev's 1989 visit to Beijing marked the dissipation of Cold War animosity[8]. After the Soviet collapse, Russia became an important economic partner and source of arms for China[8]. In recent decades, Sino-Russian relations have steadily improved, driven by shared anxieties about the post-Cold War order and U.S. power[2][3][4]. The current relationship is pragmatic, based on economic and security interests rather than ideology[10]. It is comprehensive and strategic, but still short of a formal alliance[4][8]. Key features of the current Sino-Russian partnership include: - Increasingly aligned positions on major international issues[2][5] - Growing economic ties, though interdependence is still relatively low[4][8] - Close cooperation on energy, arms sales, the Arctic, and Central Asia[8][10] - Mutual support for each other's territorial claims and at the UN[10] However, differences and distrust remain beneath the surface[3][4]. The future trajectory of the relationship will depend heavily on the international system and China's ties with the U.S.[4]