"The Great Game is played between the Bazaar's Masters, the surface cities, and other powers. Spies and assassins are their pawns."
Spies tend to pray to St. Joshua, their patron saint; the most experienced have shrines to him that are wrapped in irrigo, so they forget their secret rites after learning and performing them every time.
We know from the spies which nations are still at least somewhat intact on the Surface: Germany (or at least Prussia), France, Italy, Russia, and perhaps a diminished remnant of the British Empire. Austria-Hungary also still participates in the Great Game, and much clandestine activity happens in the city of Vienna, on the Surface.