What is the theme in Gulag: A History by Anne Applebaum?

Brutality is the main theme in the story. Virtually every chapter in the Gulag discusses the oppression, severity, and brutality of the Gulag camp system. This terror was both physical and psychological. Physically, prisoners endured exhausting labor in extreme cold, savage beatings, little amounts of food, and executions. Torture was common during interrogations in the late 1930's. Millions of people were killed within the system by starvation, dangerous working conditions, and by other prisoners, guards, and camp authorities. Women were raped and children were left with little care in the camp nurseries. Prisoners' memoirs reflect the physical hardship within the camps.