The original question had to be edited down. I would suggest that the Soviet Union's prison system in the form of the Gulag represented so much of psychological techniques of control to demonstrate to everyone that the centralized form of government could not be destabilized. The use of the psychological form of control could be seen in the employment of physical labor. Due to the fact that much of the Soviet plan for modernization involved clearing out the rural condition of the nation, inmates of the gulag had to endure physical labor that was channeled to making the nation "advance." This use of physical labor was a psychological tool of control. It conveyed to the "traitor" that no matter what, their efforts would be used towards the advancement of "the Motherland." An example of this would be logging practices in which prisoners would have to clear out a dense area of trees, only to realize that they were surrounded by forest all around then, confirming the psychological condition that there was no escape. The use of psychological terror was seen in the fact that those sent to the gulag never returned. This helped to keep the Soviet citizenry under control, never to speak out against the government in order to avoid the fate of the gulag. This represents how the psychological form of terror was employed by those in the position of power in the use of the gulag as a form of control of both those inside and outside of it.