“They [Social-Democrats] are just as much traitors to socialism… They represent that top section of workers who have been bribed by the bourgeoisie… for in all the civilised, advanced countries the bourgeoisie rob—either by colonial oppression or by financially extracting ‘gain’ from formally independent weak countries—they rob a population many times larger than that of ‘their own’ country. This is the economic factor that enables the imperialist bourgeoisie to obtain superprofits, part of which is used to bribe the top section of the proletariat and convert it into a reformist, opportunist petty bourgeoisie that fears revolution.”
— V.I. Lenin, “Letter to the Workers of Europe and America,” Pravda; No. 16, January 24, 1919.