The book "The War of 1920" was written by the Polish statesman and politician, the founder of the Polish army, Józef Piłsudski (1867-1935). This is a response to a course of lectures published in 1923 under the general title "Campaign for the Vistula," given for cadets of the Red Army Military Academy by the commander of the Western Front M.N. Tukhachevsky. The events described in Pilsudski's book relate to the 1920 campaign - the Red Army offensive under the command of Tukhachevsky on Warsaw and the subsequent Battle of Warsaw in August of the same year. The author gives an assessment of Tukhachevsky's book, comparing the views of the commanders of the warring parties, as well as their approaches to describing specific events. The work is a valuable historical material, which reflects the thoughts and actions of a talented military leader, an analysis of the activities of managing troops is given.