During the Chinese civil war between the CCP and the Guomindang (Nationalists) during the 1920ss and the 1930s, Stalin supported the Guomindang. He did this because he saw that the nationalists seemed to offer a better opposition to Japanese expansion in China. Hence for the soviets, national interests took precedence over ideological solidarity. But it is important to note that Stalin did see the CCP an important partner in ensuring the victory of world socialism and after 1945 he gave support to the CCP. When the Communists did take over China in 1949 the USA viewed it as another victory for the forces of world communism. Additionally, Mao was seen as an instrument in the USSR’s bid to spread worldwide revolution. Mao believed that an alliance with the USSR would ensure that Communist China would receive the protection it needed against attack from the USA and anti communist forces in China. This was all clearly ideological.
The Sino-soviet treaty in 1950 shows that relations were improving but they were limited in some sense as well. This can be seen by the dispute over Taiwan. The relationship at this time between the USSR and China was the ‘big brother’ mentality. In the war in Korea, 900,000 are dead, most of which are Chinese. Here we can see that he is being treated unequally. Stalin retained authority to intervene and didn’t place any soviet troops in Korea. This leads us to believe that the personalities of the leaders, especially Stalin led to the Sino-soviet split.
The Taiwan Crisis of 1954 and 1958 was all to do with Mao playing the USSR and America off of each other. The bombing of Quemoy and Matsu was to deliberately cause pressure on these places and to get America to intervene which would result in the USSR stepping in to stop the USA from infiltrating the communists.