Huh. Perhaps true. But completely ignorant of the impact, of the size, of the value of what a single "spy" (read also traitor") can discover (read also "reveal"

Huh. Perhaps true. But completely ignorant of the impact, of the size, of the value of what a single "spy" (read also traitor") can discover (read also "reveal"). Spies and traitors tend to discover/reveal HUGE secrets, e.g., how to make a nuclear weapon, how to crack air defense, exact plans and order of operations for critical engagements, etc. Terrorism doesn't even enter onto the same radar screen as those sorts of things, because all of the terrorism in all of the 20th C amounts to what, the effects of one atomic bomb? (Back of the envelope, not terribly accurate, but gives relevant context.) I'll stipulate that the vast majority of spies never discover anything useful. I'll further stipulate that "vast majority" involves several decimal points, i.e., 99.999% or higher. And I'll assert that it is still worthwhile having spies for what the 0.001% or 0.0001% discover - because they don't go for the low hanging fruit, they go for and get the game changers.