There is little morally to fear for all of us agreeing to keep traditional (and temporary) military secrets such as all troop movement before the planned big invasion.
By their very nature, such secrets are no longer a secret two or three days into battle.
But Enigma code-breaking, The (atomic) Bomb, the Proximity Fuse and Wartime Penicillin were all military secrets with huge moral costs attached.
Enigma was only kept secret for so long by sometimes deliberately not revealing to the effected military units the grim fate before them that the code-breaking revealed --- all in an attempt to keep the code-breaking secret from the enemy long enough for code-breaking to reveal (and foil) huge plans by the enemy.
This moral dilemma has kept the Enigma industry churning out lots of books and movies, 75 years after the events.
Proximity fuses were so wonderful that we couldn't use them against the Germans, convince they would find one unexploded and quickly duplicate it and then use it to horrible effect against our bomber streams because it was actually more useful to them than to us.
This is the same dilemma that the Germans faced about the nerve gas they invented, because they rightly feared we could make better use of it than they could --- so they never used it and kept it secret.
(At least the Germans didn't put much effort into producing nerve gas because it more or less fell into their laps- while proximity fuses were one of the single biggest scientific and engineering effort of the entire war - in my view, a mammoth mis-allocation of scarce war resources.)
The Atomic Bomb could not remain a 'secret' for very long once it was used, because it was seemingly so war-endingly successfully.
Hence nations big enough to afford it simply felt they had to pour immense amounts of money, expertise and national willpower into duplicating what the Americans had hoped to keep secret for at least a generation.
The entire American civic culture changed, for the worse, when the American atomic establishment decided atomic information could actually be "born secret and kept secret government property", even at the moment a new concept first formed in a scientist's mind !
What really kept the Bomb a 'secret' , quote unquote , is the expense and complexity of making it consistently successfully.
Everyone on Earth had heard of The Bomb, knew what it did , what it was made up and even basically how it worked : the American government had showed them all this in the public Smythe Report.
But a successful Bomb, like the Devil , was in the details ; these were complicated, expensive and remained secret to all but the best foreign spies.
And this - presumably - was how the Allies expected to keep the "Penicillin Secret" once they unleashed it as a secret medicine weapon only for Allied frontline casualties on D-Day (if Patty Malone and that damned beta-lactam ring hadn't spoiled the plan).
Who could really expect to keep the good news about penicillin's life-saving powers away from the general public (aka the relatives of frontline troops), as soon as millions of Allied casualties were coming back home alive, while enemy POWs from the same battle were dying like flies ?
No, like The Bomb, penicillin would quickly become uniquely famous all around the world and only remain a 'secret', quote unquote, because the Allied scientific elite figured that the information as how to make it could remain secret from the enemy for at least a year, because it was complex and expensive.
Remember, even the atomic bomb secret was broken in the end, but only about six years after it became first known to Britain, France and Russia that an A-Bomb would likely work.
That's the length of the entire (long drawn-out) WWII.
So a permanent military secret kept for as short a time as a year long, might still be viewed as long enough to be militarily effective.
But penicillin was no where as complex or as expensive as proximity fuses or nuclear weapons : in fact, it is a piece of cake for every and any hospital bacteriology lab to make safely and cheaply, in amounts sufficient to save the lives of all the people in that hospital dying of infections no other medication could help.
In normal situations, those really are not large numbers, spread over an entire year and over an entire country: in peacetime, there needn't ever be a penicillin crisis, for least for the dying of infections would get it when they really needed it.
But a huge invasion like D-Day requires an extraordinary amount of penicillin over a few days or weeks, in a small area , under fluid combat conditions that obviously doesn't allow much in the way of crude penicillin-making labs in sedate base hospitals.
So war weapon (frontline battle) penicillin really did require a lots of stable penicillin in a dry power, to be useful.
But in fact, even without Patty Malone to tip them off, as soon as word of penicillin great success got about, the enemy would start making it by the crude means known in the vast amount of public literature on penicillin.
But the cost of keeping penicillin a non-public success before unleashing it on D-Day, was in denying it for civilians in Allied,Neutral, Occupied and Enemy countries for years and in fact, in denying it to ordinary soldiers dying of infections penicillin could cure, again between 1940 and 1944.
That is literally millions of needless deaths --- at least as much as the Jewish Holocaust.
It was and is , a horrific moral crime, a deliberate crime promoted by doctors.
And it is why I write about wartime penicillin , 75 years after its events...