It's the reason that the relationship developed the way that it did which is different (China only became an enemy by being a success outside of the imperialist order, while Russia was a never fully defeated enemy which desired to join the imperialist order but was unallowed without greater concessions/poverty to the imperialists). You're thinking in simple metaphysical categories. Rod_blagojevic (hopefully) means that China isn't a bourgeois dictatorship which is why SUCCESSFUL DEVELOPMENT has led to its enemy status. Russia is a bourgeois dictatorship which is an enemy because of its RESISTANCE. It's the process which is determinant and the category which provides the frame within which the process is understood.