Bullshit. Who says anything about punishment. They are being punished, then there MAY come a choice. If you are so hell bent on "deterrence" look after presidential pardons. And if you do not save your own spies given a chance, the next one you want to hire will direct you straight to the place where the sun does not shine
>"One should not exchange spies for the cost of increasing political assasinations. Same reason as why you shouldn't pay kidnappers."
I strongly disagree for it to be used as a general approach for either spies or kidnappers. And who says it is exactly the cost? It is all coulda shoulda woulda and depends upon the particular situation.