I really don't understand what you're trying to argue with this statement.
That you're defining class struggle to fit any other type of struggle. The fact that the majority of struggles aren't class related would otherwise seem to be evidence against the Marxist view.
That's not what I said, I said that the national contradiction arises first. Once the national contradiction and the colonized power becomes independent, then the more concrete questions of relations of power inside of that community make themselves plain.
Sure, but why not then say that conflict between two nations or ethnic groups is more fundamental than that between the rich and the poor?
A similar thing happened in the golden era of liberal revolutions: 1848. The February Revolution created the Second French Republic, and in that event the bourgeoisie, peasantry, and proletariat were united against the monarchy. The mood was one of creating a Democratic and Social Republic for all Frenchmen. But the sharp conservative turn in the summer destroyed this illusion, and the proletariat realized that the bourgeoisie were not interested in this republican brotherhood, and the working districts of Paris erupted in terrific violence against the regime in June. While they had a common cause they were united, but once that was achieved the unity of cause was gone and they turned on each other. Marx observed these days and wrote that February was the "beautiful" revolution but June was the "ugly" one, because it was so much the more personal. Tocqueville observed that the goal of the revolutionaries was not to change the type of government (as had been accomplished in February), but, for the first time, to change the organization of society itself.
And that is the difference between national liberation and class liberation.
Let's apply this, then. People in a colonized country revolt against their perceived oppressors, kick them out, but then realize that the oppression is still ongoing. So they turn to socialism and its various ideologies, or at least pay it lip service.
This makes sense as a narrative, but we're not talking about internal politics of countries, as I said; we're talking about the imperialism that precedes the class struggle of decolonized nations. You're arguing that imperialism is a huge component of capitalism but at the same time dismissing the reactions to imperialism which do not assert such.