Who is O’Brien? How does Winston regard him?

O'Brien is a prominent Inner Party member with whom Winston feels a strange bond. Winston feels that even if O'Brien is an enemy, it wouldn't matter because he knows O'Brien will understand him without explanation. O'Brien is a large, graceful, and clearly intelligent man who leads Winston to believe he is part of an underground movement against the Party, but in fact helps turn Winston in for thoughtcrime and tortures him in the Ministry of Love. O'Brien is full of strange contradictions. He can be fatherly - and even tender - even while fanatically expressing his devotion to the Party by torturing Winston.