For something that's supposed to be secret, there is a lot of intelligence history. Every time I read one book, two more are published.

In the 1930s, there were so many different conflicts going on between the British, the French, the Russians, the Germans, the Spaniards, the Romanians and so on.

I don't just want my books to be about the '30s and '40s. I want them to read as if they had been written then. I think of them as '40s novels, written in the conservative narrative past.

For John le Carre, it was always who's betraying who: the hall-of-mirrors kind of thing. When you go back to the '30s, it's a case of good vs. evil, and no kidding. When I have a hero who believes France and Britain are on the right side, a reader is not going to question that.