(Read here )
(Written from anti-communist perspective)
Sun Yat-sen's decision to ally with Russia and CCP was induced by the antagonisms from the imperialistic powers. Sun Yat-sen complained to reporters of "New York Times" in July, 1923 about this kind of imperialistic antagonisms towards the Chinese revolution.
From the outset of Xin Hai Revolution of 1911, imperialist powers had opposed China's democracy process, and this is best exemplified by US ambassador's pressuring Manchu government into recalling Yuan Shi-Kai for sake of cracking down on Xin Hai Revolution. That is what I will call here as the Tragedy of Chinese Revolution, not the same as Harold Isaacs' book Tragedy of The Chinese Revolution, i.e., Chinese revolution failed as a result of the ideological difference between Lenin, Stalin, Bukharin and Trotsky on the matter whether China's revolution was at the stage of Russian 1905 Revolution or Russian 1917 Revolution.