The power of paranoia is amazing, and the director of the German psychological drama The Lives of Others knows this. Fear of the unknown remains the greatest psychological stricture since, without knowledge of what to be wary of, courage can find no real frame of reference. Naturally, such vague dread is the perfect mechanism for total control. Apply enough pressure, and threaten the ethereal element of existence, and you can keep dissent down to a bare minimum, if it exists at all.
This was the way most supposedly sovereign satellites of the USSR did business. While the amazing might of Russian forces could be called up at any moment, a far more sly and sinister form of tyranny was being used. What these oppressive nations learned was that, when faced with losing their lot in a very limited social setting, or snitching on their friends, families, and coworkers, a human being became a rather easy and readily available nut to crack.