The problem with spies of any stripe is that you can never know if they're lying. Le Carre's books do the best job of communicating this depressing fact, I thin

The problem with spies of any stripe is that you can never know if they're lying. Le Carre's books do the best job of communicating this depressing fact, I think. So if you can't know whether they're lying, any information they provide is just noise ultimately, because you'll very rarely (like never) beat them at their game; and if you do, they'll change the game.