China immigrated to the Soviet Union by nuclear means.

At that time, Sino-Soviet relations were subtle, but they were not enemies. Moreover, during Stalin's period, China and the Soviet Union signed a new treaty, which included the border issue between the two sides and the independence of outer Mongolia. So there is no doubt that the Soviet Union is afraid that China will return to its territory.

After Stalin's death, the Soviet leadership continued its fierce power struggle. In order to defeat his political enemies, Khrushchev actively adjusted his China policy and needed China's help in dealing with the Eastern European issue.

1954, 10 During Khrushchev's visit to China in June, when he provided China with a series of questions about other requirements of China, Mao Zedong took the opportunity to express his interest in atomic energy and nuclear weapons, and hoped that the Soviet Union would help him in this regard. Khrushchev was unprepared for this sudden problem. After a moment's hesitation, he persuaded Mao Zedong to concentrate on economic construction and not engage in such expensive things, and said that as long as there was a Soviet nuclear umbrella, it would be enough. But Khrushchev finally promised that the Soviet Union could help China build a small experimental nuclear reactor, conduct scientific research on atomic physics and train technical force.

Objectively speaking, the Soviet Union's help to China is enormous and selfless. Especially during Khrushchev's administration.

The deterioration of Sino-Soviet relations should be entirely attributed to China.