Trotsky’s response to the December 1, 1934 assassination of Leningrad Communist Party leader Sergei Kirov and the series of accusation that would follow is not just a statement on that event, but a description of forces that allowed for the Great Purges that would soon come. Online text linked here.

The Kirov Assassination by Leon Trotsky. Pioneer Publishers, New York. February, 1935.

Contents: The Stalinist Bureaucracy and the Assassination of Kirov: A Reply to Friends in America, A Grandiose “Amalgam,” Are Zinoviev and Kamenev Terrorists?, Was the Purpose to Restore Capitalism?, Nicolaiev’s Crime Is No Accidental Event, Socialism Has Not Yet Been Built; the Roots of the Classes Have Not Yet Been Extirpated, The Dual Role of the Bureaucracy, The Two Series of Difficulties, Individual Terrorism- a Product of Bureaucratic Decay, Marxism Terrorism and Bureaucracy, Bureaucratic Centrism the Cause of the Collapse of the CI, The World-Wide Growth of Genuine Leninism is a Dreadful Danger to Stalin, The Inevitability of New Amalgams Had Been Foretold, Several Conclusions, Several Conclusions. 32 pages.

Pioneer Publishers was the publishing house established by the Communist League of America (Opposition) in 1930. It later served the Socialist Workers Party and was superseded by Merit Publishers in 1965, and later by Pathfinder Press in 1969.

PDF of pamphlet: https://archive.org/download/1935-kirov-assassination-leon-trotsky/1935%20-%20Kirov%20Assassination%20-%20Leon%20Trotsky.pdf