The aggravation of the class struggle along with the development of socialism is a component of the theory of Stalinism. The theory was one of the cornerstones of Stalinism in the internal politics of the Soviet Union. Although the term class struggle was introduced by Karl Marx and Friedrich Engels and the aggravation of the class struggle was an expression originally coined by Vladimir Lenin in 1919 to refer to the dictatorship of the proletariat, the theory itself was put forward by Joseph Stalin in 1929 and supplied a theoretical base for the claim that ongoing repression of capitalist elements is necessary. Stalin believed that residual bourgeois elements would persist within the country and that with support from Western powers they would try to infiltrate the party. A variation of the theory was also adopted by Mao Zedong in China (Continuous Revolution theory). Vladimir Lenin believed that the Russian Civil War represented the peak of the aggravation of class struggle which found its representation in the Soviet dictatorship of the proletariat and that by war's end and the victorious establishment of a workers' state in Russia the bourgeois class was effectively rooted out and therefore the theory no longer applied in that country. On the other hand, Joseph Stalin argued that the further the country moved forward in constructing socialism, the more acute the forms of struggle that would be used by the doomed remnants of exploiter classes in their last desperate efforts. Therefore political repression was necessary to prevent them from succeeding in their presumed goal of destroying the Soviet Union. Stalin put forth this theory in 1929 in the special section of his speech "The Right Deviation in the C.P.S.U.(B.)" at the plenum of the Central Committee and Central Control Commission, C.P.S.U.(B.) held 16–23 April 1929, which concluded: The dying classes are resisting, not because they have become stronger than we are, but because socialism is growing faster than they are, and they are becoming weaker than we are.