In Russia, the Mensheviks believed the two-stage theory applied to Tsarist Russia. They were criticised by Leon Trotsky in what became the theory of permanent revolution in 1905. Later when the two-stage theory re-appeared in the Soviet Union after the death of Vladimir Lenin, the theory of permanent revolution was supported by the Left Opposition. The permanent revolution theory argues that the tasks allotted in the two-stage theory to the capitalist class can only be carried out by the working class with the support of the poor peasantry and that the working class will then pass on to the socialist tasks and expropriate the capitalist class. However, the revolution cannot pause here and must remain permanent in the sense that it must seek worldwide revolution to avoid isolation and move towards international socialism.