Winston Smith lives in a totalitarian society called ingSoc or English Socialism, which rules England. Every bit of literature except propagandistic one, science except military one, any traces of humanity and compassion are forbidden entirely. You cannot keep even a personal diary. Instead what you have to have is hatred against an enemy and nothing more.
There’s a war between Oceania, Eastasia and Eurasia. This war is different for it is started not to achieve a victory over the enemy in the old sense of word but to maintain civil unrest, to keep forever the hierarchic system of power and control over the subdued masses that are called the prols or proletariats. IngSoc alters books, articles, statistics, people’s minds, everything, even history. The prols believe that they had overthrown old capitalists and became the true history makers whilst they are not.
The Party (well-deserved analogy to communist one) kills and humiliates anyone who even started thinking in not a favourable way to the regime. There is no difference in the eyes of the Party between a thought and action. You think another way, you’ll be vaporized in every sense of the word. The Thought Police will see to that. The sex is forbidden. Love is tolerated as long as it can produce children, future soldiers or mothers of soldiers.
Winston is loathing all this. He wants a freedom in everything, in thoughts, in actions, in literature, in social life. He rebels against oppression and wants emancipation. He joined a rebellion movement called Brotherhood. Maybe that’s one of the reasons why the writer also included a sexual life between Winston and Julia into the book. Winston and Julia were captured, tortured and humiliated. in the end They betrayed each other. This betrayal is slightly described not as a weakness against physical torture but as a normal thing when it comes to the mind torture. I kind of advocate this betrayal in the book so that the readers can fully grasp the sufferance and anguish the people of the totalitarian states must endure all their life.