The Spy Who Came in from the Cold

Evaluate John le Carré’s description of the British Intelligence headquarters as the “Circus.” Why does he use that term as a shorthand for British Intelligence? 

What conclusions does the book reach regarding the nature of the Cold War? Is there any meaningful difference between the two sides?

Why does Liz maintain her connection with and affection for Leamas despite his harsh treatment of her? What does the early phase of their relationship say about their characters?