Complex sentence: The "internationalist" perspectives of Bolshevism and Marxism are based upon the class struggle that transcends nationalism, ethnocentrism, and religion--intellectual obstacles to class consciousness--which the ruling classes manipulate to divide the working class.
Split into simpler sentences: The "internationalist" perspectives of Bolshevism and Marxism are based upon the idea that a class struggle transcends nationalism, ethnocentrism, and religion. These are regarded as intellectual obstacles to class consciousness, obstacles which Marxists believe are manipulated by the ruling classes to divide the working class.