Re: BBC programme
"So why is it vital to keep Bletchley secret from the Germans in 1979?"
To play the devil's advocate here - it's choice 4, plus the fact that "knowledge is power", exclusive knowledge exponentially so; therefore even if it wouldn't actually matter a miserable iota whether anyone else knew or not, them *not* knowing is demonstrably, quantitatively *moaaaar power* than letting them know - so obviously we don't, even if we have no other justification whatsoever to keep it secret. Which is not even the actual case - you listed a few reasons yourself...
Biting the hand that feeds IT
