“Terrorists and Spies should always be executed upon conviction. This would prevent future efforts to do a prisoner exchange, and may also deter people from entering this line of work...”
You’ll get no disagreement from me - especially when the spy in question is one of our own citizens.
For example, I cite as examples...
Robert Hanssen, Christopher Boyce, Aldrich Ames.
All three of them should have received the death penalty. I have no sympathy for traitors in our midst. I don’t care whether they did what they did for ideology or for money.
The threat of death may not deter all possible traitors - but it should deter a great deal of them.
Put Larry Franklin in a cell with those bad boys and they'd have a foursome for bridge.