I think I said something like "Not all, not to all extend, and not immediately." And I meant it
But right now the minimum closure time for secret files is 50 years!
How in the world is a democracy supposed to react to that?
And this tells how quickly I think we need the information: Quickly enough to react to it. That can have several levels actually.
While operations are running, we need to know stuff like "Hey, we use herbicides to starve out the Korean guerrillas. ok? It might be a bit poisonous, but we think it gets the job done." This is an information we need to know right now when it happens. There is no risk in getting this information except the risk that your population says "No, that's cruel and against the rules of war."
Of course there is no need to release the plan where to drop how much of the stuff, or any other detail of the operation.
Not until the war is over. But after the war is over there is no reason to hold back the informations (except maybe for names)
Same goes for spying, whether on Allies or foes. The population should be able to know whether you are spying on your allies to make sure they do not spy at you, or whether you spy on your allies to give Monsanto a competition advantage.
Whether you spy your foes to prevent terror attacks or whether you are preparing an assassination.
And with time more and more information should be released, as much as possible without risking too much.
And if that takes 50 years to be save, so be it... but no generalized, preventive 50 year closure for everything.