In Marx and Engels’ opinion，the essence of the western globalization is the fundamental contradiction all over the world between capital and labor. The fundamental contradiction between capital and labor all over the world determines that liberation of labor is not a problem in a region，a country，but a social problem concerning all countries. It also determines that socialism is not only a problem of region，but also an international problem. The liberation of labor requires close unity of world proletariat. Young proletariat，especially the proletariat of western countries must watch out for instigation of the western bourgeoisie，should be on alert for making mistakes of national prejudice and national egocentrism，which is a big enemy of getting in the way of building strongly international unity of proletariat.