Only when the kulak refused to deliver grain to the State did [Joseph] Stalin, under the pressure of the Left Opposition, accomplish a sharp turn. Being the empiricist that he is, he moved, to the opposite extreme, and set as a task for two or three years the collectivization of all the peasantry, the liquidation of the kulaks as a class, and the compression of the Five Year Plan into four years.

Writings of Leon Trotsky: 1932 (ed. 1932)