"Stalin was confident enough to make jokes about his terror, as he did with de Gaulle, but his jokes about terror are grim and ‘usually no one laughed'. An example was ‘about a Chekist and a professor who lived in the same apartment [block]. One day the professor, irritated by his neighbor's ignorance, exclaimed, "Oh, you! You don't even know who wrote Yevgeny Onegin!" [Aleksandr Pushkin did] The Chekist felt insulted (because he really did not know). Soon afterward he arrested the professor, boasting to his friends: "I got him to confess it! He was the author!" ' Another concerned Stalin's pipe. Stalin complains that he has lost his favourite pipe, saying that he will give a handsome reward to whoever finds it. A few days later Beriia calls Stalin, telling him that his pipe has been found. Stalin replies that he has found his pipe himself under the sofa. Beriia exclaims, ‘It can't be! Three people have already confessed to stealing it!'
Characteristically, Stalin used the threat of terror for communication. During the war, Nikolai Baibakov, then a 31 year—old Deputy People's Commissar for the Petroleum Industry, was told by Stalin that if he surrendered even a ton of oil to the advancing Germans in the northern Caucasus, he would be shot, but then again if he destroyed the oil wells prematurely, leaving the Red Army without oil, then he would be shot all the same. Stalin's threat was not a joke, and Baibakov was very likely horrified. As terrible as it was, the threat was almost certainly not meant to be taken literally — it was Stalin's way of communicating the gravity of the task to Baibakov. Stalin never stopped using terror, but in cases like this he appeared to use it metaphorically because now he could afford to do so. In 1937—8 he had summarily killed hundreds of thousands of people without so much as a threat."
--- Stalin / Hiroaki Kuromiya