What is the central conflict of Winston's behavior at the end of the story 1984?

The central conflict at the end of the story is Winston's love for Julia.  Even when the brain washing begins to take hold over Winston's mind, he remembers Julia and his love for her.  This love is what forces O'Brien to send Winston to Room 101.  In that room, under the threat of rats, Winston finally betrays his feelings for Julia and mentally sacrifices her to the rats.