“theory of national revolution” - China cannot carry out proletarian-socialist revolution without first going through national revolution, i.e., bourgeois-democratic revolution; and the proletariat must strive for the leadership of the national revolution.
before and at the first Congress there was no theory – not even a glimmering of one – about first having to complete bourgeois-democratic revolution before starting proletarian-socialist revolution. After the First Congress the question of cooperating with the Guomindang was raised. It was discussed at the Second Congress and again at the West Lake Conference, and the Third Congress decided to join the Guomindang. But it was raised as a tactic, in terms of how can we even more quickly and effectively develop the revolutionary movement and Party forces
Were there grounds for such a theory? Yes, people cited the theoretical disputes in Russia before the Revolution as a basis for it. But they avoided talking about the actual course of events in 1917, for that showed that the Russians had already carried out the proletarian-socialist revolution even before completing the bourgeois-democratic one, that bourgeois-democratic revolution in Russia was completed as a by-product of proletarian-socialist revolution. – an earlier stage of a revolution is a by-product of the higher one.