On July 16, 1960, the Soviet Union officially notified the Chinese Ministry of Foreign Affairs that it would recall all Soviet experts working in China within a time limit, as well as destroy some core drawings, tear up all economic contracts with China, and at the most difficult time in China, that is, the worst period of the three-year natural disaster situation, the Soviet Union forced China to return the arrears and all kinds of arrears of materials, hoping to completely crush China.

China and the Soviet Union are all socialist countries and should support each other and help each other, so why did they finally come to this step? Breaking with the Soviet Union and not having good relations with the United States led to China's extremely difficult situation in the international community, so what was the reason that China at that time chose to completely tear its face with the Soviet Union and leave no room for maneuver? There are many reasons for the breakdown of Sino-Soviet relations, but there is only one fundamental reason.
As early as the period of the agrarian revolution, there were already contradictions between China and the Soviets, the revolutionary line of the Communist International with the working class as the core was completely inconsistent with China's national conditions, China did not have so many working classes, and finally decided to launch a peasant revolution. After the founding of the People's Republic of China in 1949, China implemented a one-sided policy in diplomacy and fell to the Soviet camp in an all-round way.
Although there have always been some small frictions between China and the Soviet Union, but it is a controllable and reconcilable contradiction, and it belongs to the internal contradiction, the relationship between the two sides is still very good, and after Khrushchev came to power, he made a "secret report" incident, after which there were obvious contradictions in the ideology of China and the Soviet Union, the quarrels began to escalate, and the contradictions that were difficult to reconcile also made Sino-Soviet relations begin to decline, but this was not the fundamental reason for the rupture of Sino-Soviet relations.
In April and July 1958, when the Chinese demanded that the Soviet Union provide the nuclear submarines and nuclear weapons that had been promised to China, the Soviet Union at that time wanted to engage in "feudal patriarchy" and wanted to use other allies as cannon fodder in the struggle with the United States. Moreover, the Soviet Union did not want to hand over nuclear weapons technology to China, so it proposed a quid pro quo, requiring the establishment of a long-wave radio station in Hainan, China, to command nuclear submarines, and to form a Sino-Soviet joint fleet.
Looking at today's South Korea, we can understand that the real idea of forming a combined fleet is to control China with military force and encroach on China's sovereignty! At any time, no matter who, as long as there is this idea, China dares to turn its face directly. The issue of sovereignty was the root cause of the rupture of Sino-Soviet relations, and since then, the contradictions between China and the Soviet Union have gradually escalated.
From 1963 to 1964, the Chinese side published nine articles criticizing the Soviet Union, at which point the level of debate between the two sides reached its peak, and in 1968, with the increase of soviet troops on the Xinjiang border, the contradictions between China and the Soviet Union also escalated from verbal quarrels and ideological confrontations to direct military confrontation. Many Western countries believe that a large-scale war will break out between China and the Soviet Union sooner or later, but in the end, the three sides of China, the Soviet Union and the United States formed a triangular relationship, achieved a certain balance, and alleviated some contradictions.
The Soviet Union collapsed in 1991, but China's development was orderly and gradually getting better. Looking back on this period of history afterwards, we still feel thrilled, just from some limited historical fragments of information, we can know that China's situation at that time was very difficult, the domestic economy was not good, the international was still isolated, we needed to solve many domestic and foreign problems, and the difficulties we faced were also very great, but our leaders not only took us out of the mud step by step, but also created one economic miracle after another.
China is truly a great country.