On 15 August 1936, the Great Purge began in Moscow with the trial of 'the Trotskyite-Zinovievite Terrorist Centre'.
Throughout the decade of the 1930s the duel between CPSU General Secretary Josef Stalin and Leon Trotsky occupied the centre of the Soviet political scene. From various places of exile in Turkey, France and Norway, Trotsky ceaselessly attacked Stalin. The Bolshevik hierarchy - Trotskyists, Zinovievists, Bukharinists and Stalinists listened intently to every word of the founder of the Red Army. In Bolshevik eyes, Trotsky represented the sole alternative to Stalin and Stalinism; and so the whole Stalinist propaganda machine concentrated immense eftorts upon discrediting him. Stalin carried the anti-Trotsky campaign into every sphere of thought and activity both within the borders of the Soviet Union and abroad, among the Comintern apparatus abroad. The campaign reached its climax in 1936-38 when the world was treated to the spectacle of the Moscow Trials, of which Trotsky, was 'tried' in absentia.
Nearly all the leaders of the October Revolution, all members of Lenin's Politbureau, most commanders of the Red Army, scientists and writers were denounced as terrorists, murderers, and wreckers, as foreign spies and traitors, and executed. Andrey Vyshinsky was the Prosecutor General.
During the Terror 3 million people were arrested on various and often made-up charges, while 750,000 were executed. Due to the interrogation techniques of the NKVD (later, KGB), which often were torturous, most of those arrested confessed and were sent to work camps, called the Gulag for 10 years and sometimes even 25. Here, prisoners were forced to labor in mines, to log forests, or to do construction. Few lived through their sentences.
Stalin eviscerated the high command of the Red Army, killing 90% of the senior leadership. This would have disastrous consequences for the USSR in 1941 when Germany invaded the country. Those responsible for the apparatus of state oppression were not spared, either: of the NKVD's 809 high officials, only 43 lived through the purges. According to KGB defector Alexander Orlov, more than 3,000 NKVD officers were shot in 1937 alone. 
The leadership of the communist party was persecuted as well. For example, in 1934 130 members of the 139-member Central Committee were arrested. The Terror forever made Soviets afraid to speak out against the government, and also made sure that no one but Stalin could ever rule the Soviet Union as effectively.
Propaganda in the United States
Mary Van Kleeck in the Institute for Pacific Relations journal, Pacific Affairs espoused the official Soviet version of the Stalinist terror. KGB Operative Owen Lattimore defended the show trials in Moscow in the same publication as "an evidence of democracy."
- Isaac Deutscher, The Great Purges, edited by Tamara Deutscher (Basil Blackwell, Oxford, 1984), p. 72.
- Deutscher, The Great Purges, p. 69.
- Deutscher, The Great Purges, p. 6.
- Alexander Orlov, The Secret History of Stalin's Crimes, (New York: Random House, 1952), p. 216.
- Pacific Affairs, September, 1938.