# Did the Allies knowingly send men to death to avoid revealing the cracked enigma? **URL:** \ **Category:** Factual Questions\ **Created:** [May 16, 2002, 1:24pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375 "2002-05-16T13:24:19Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![jkirkman](https://avatars.discourse-cdn.com/v4/letter/j/ac8455/32.png) [@jkirkman](https://boards.straightdope.com/u/jkirkman)\ **Post date:** [May 16, 2002, 6:16pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/21 "2002-05-16T18:16:57Z")
> [@](#): > > \*Originally posted by London\_Calling \* > \*\*If memory serves, one of the biggest cases of this was the bombing of Coventry - IIRC and according to Churchill’s driver, he opened the envelope containing the information while driving out of London and, when he found out, had the car turn around. > > No one in Coventry was informed of what was going to happen that same night. \*\* Well, I have heard this story a zillion times, and it is in a lot of History books (and even on the town of Coventry’s web page!), but there is a good deal of doubt about the veracity of this story AS COMMONLY TOLD. A conflict the size of WWII generates an enormous amount of military radio traffic, and sorting out time-sensitive operational orders from other traffic is not an easy task. By the time they had the exact details of the raid figured out, it was a bit late to evacuate cities or shuffle forces around. Instead they relied on electronic counter-measures (which failed) and the normal fighter intercepts (which failed). From the _Oxford Companion to World War II_, edited by I.C.B. Dear & M.R.D. Foot (Oxford U. P. 1995)'s entry on Coventry (p. 275) ". . .attacked on the night of 14/15 November 1940 by German bombers employing for the first time, their Pathfinder force KG100, and the X-Geraet beam system for finding their targets. ULTRA intelligence and prisoner of war information forewarned the British of a major Luftwaffe operation (Moonlight Sonata) against a number of their cities. These included Birmingham, Coventry, and Wolverhampton, but the information was not correlated and there were also indications that the targets might be in London and the south of England. In any case, it was impossible to tell which would be attacked first and the ENIGMA signals giving their direction to the stations emitting them were not broken in time. By 1500 on the day of the raid the beams were found to intersect over Coventry, but electronic counter-measures failed to work as the jammers were incorrectly set. The fact that Coventry was to be the target that night was passed on to RAF Fighter Command but 'British counter-measures proved ineffective: of the 509 bombers the German Air Force dispatched to Coventry, 449 reached the target and only one was certainly destroyed (F. H. Hinsley, \_British Intelligence in the Second World War, Vol 1., London, 1979, p. 318). This failure probably hasten the departure of Dowding from Fighter Command and from it grew the myth that Coventry was left to the mercy of the Luftwaffe in order to protect the secret of ULTRA" Also see Ronald Lewin in “Ultra at War” (Pocket Books paperback edition, pp. 98-103). “The Ultra intercepts did not state that Coventry was to be bombed; they specified a target by a coded designation which the British could not interpret; they in fact believed the attack would be on London or the southeast. Also note DeWeerd, Harvey A. “Churchill, Coventry and Ultra.” Aerospace Historian 27 (Dec. 1980): 227-229 -jack ---
**Author:** ![jkirkman](https://avatars.discourse-cdn.com/v4/letter/j/ac8455/32.png) [@jkirkman](https://boards.straightdope.com/u/jkirkman)\ **Post date:** [May 16, 2002, 6:21pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/22 "2002-05-16T18:21:34Z")
Oh man, I wasn’t clear. London\_Calling, I was not referencing the Churchill/Driver part of the story. I was talking about the common “Churchill knew of the Coventry raid in time to do something about it but allowed civillians to die to protect Enigma story.” You did not make this claim, and I did not mean to imply that you did. Sorry. –jack ---
**Author:** ![JaxBeachBoy](https://avatars.discourse-cdn.com/v4/letter/j/e19adc/32.png) [@JaxBeachBoy](https://boards.straightdope.com/u/JaxBeachBoy)\ **Post date:** [May 16, 2002, 6:55pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/23 "2002-05-16T18:55:14Z")
Go read “Cryptonomicron” by Neal Stephenson. It’s my favorite book ever, it deals with date encryption now, but tells a parallel story to the first days after we had the Enigman machine. It IS a work of fiction, but tells the story of how we had to figure out how many Uboats we could intercept, and still make the Germans think it was coincidence…some of the stuff is pretty amusing…he has us setting up a fake listening post in Italy, carrying in trash, papers, etc…to make it look like we had been there for months, and then purposely allowing it to be discovered, to lead the Germans to believe we had gotten info. that way. Some of it could be true, but it is presented as fiction, and deals with the very topics you have brought up. ---
**Author:** ![bonzer](https://avatars.discourse-cdn.com/v4/letter/b/45deac/32.png) [@bonzer](https://boards.straightdope.com/u/bonzer)\ **Post date:** [May 16, 2002, 7:00pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/24 "2002-05-16T19:00:44Z")
> [@](#): > > \*Originally posted by London\_Calling \* > If memory serves, one of the biggest cases of this was the bombing of Coventry - IIRC and according to Churchill’s driver, he opened the envelope containing the information while driving out of London and, when he found out, had the car turn around. > > No one in Coventry was informed of what was going to happen that same night. R.V. Jones’ version (in _Most Secret War_, Hamish Hamilton, 1978, p150) of Churchill’s reaction to the available intelligence about the raid is as follows: > [@](#): > > Churchill that afternoon had set out from London for Ditchley Park (the house a few miles north of Oxford which he used as a retreat in place of Chequers on moonlit nights) when he opened his box containing the latest Enigma decodes. A heavy raid was foreshadowed, and Churchill at once turned the car back to London. To those of us who knew him this could mean only one thing: he thought that the attack was to be on London and that his duty, in character with his lifelong inclination, was to be where the fight was hottest. This conclusion is borne out by Sir John Martin, who was with him as Secretary in the car, and by the fact that he sent [John] Colville and Martin to take refuge in the deep air raid shelter at Down Street Underground Station, telling them that their young lives were valuable for Britain’s future, while he went up onto the Air Ministry roof. He cites a _TLS_ article from 28th May 1976 by Sir David Hunt for the details. Jones was, of course, central that evening to trying (and, by his own admission, failing) to establish what the Germans were going to do. On the more general issue of protecting Ultra, the standard practice was to fake alternative means for discovering the info, which the Germans would then infer had actually been used. Thus if an Enigma decript disclosed the position of, say, a battleship, then it would be arranged for a routine spotter flight to “accidentally” stumble across it prior to an attack. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [May 16, 2002, 8:53pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/25 "2002-05-16T20:53:07Z")
Does anyone here know if the story about Yamamoto’s assassination in Cryptonomicon is pure fiction or based on fact? I call it an assassination rather than downing since he was personally targeted and there is no perjorative connotation. But it was a dangerous thing to do since it potentially compromised the code breaking. ---
**Author:** ![London\_Calling](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@London\_Calling](https://boards.straightdope.com/u/London_Calling)\ **Post date:** [May 16, 2002, 10:11pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/26 "2002-05-16T22:11:10Z")
**bonzer** - Interesting that the passage you quote says they didn’t know where the raid was to be but assumed London. I really can’t recall where I read another account but it may have been by Churchill’s driver as _I think_ I read they only got as far as Kensington High Street before turning back – that would actually tie in given he was heading towards Oxford. FWIW, I sometimes wonder how much detail the people who were there actually remember (given how eventful was every day) and how much is later presented as historic fact by the interviewers. Difficult to say unless you hear the interviewee’s pauses and “Hmm…” 's ---
**Author:** ![Melon\_Farmer](https://avatars.discourse-cdn.com/v4/letter/m/838e76/32.png) [@Melon\_Farmer](https://boards.straightdope.com/u/Melon_Farmer)\ **Post date:** [May 16, 2002, 11:56pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/27 "2002-05-16T23:56:55Z")
Hari, my understanding is that the events surrounding Yamamoto as portrayed in Cryptonomicon were pretty accurate and that he was successfully assassinated as a result of broken encryption. And that furthermore there was a lot of hand-wringing by the allies over whether to go after him or not, but in the end it was decided that he was worth it, even if the Japanese tipped to the cracked encryption because of it. If you type Yamamoto and Assassination into Google, you’ll get back more good info about this. There’s also a good PBS Nova special about the cracking of Enigma if you ever get a chance to see it. [http://www.pbs.org/wgbh/nova/decoding/](http://www.pbs.org/wgbh/nova/decoding/) ---
**Author:** ![Rysdad](https://avatars.discourse-cdn.com/v4/letter/r/7cd45c/32.png) [@Rysdad](https://boards.straightdope.com/u/Rysdad)\ **Post date:** [May 17, 2002, 12:09am UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/28 "2002-05-17T00:09:07Z")
Just another plug for _Cryptonomicon_. Damn fine read. ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [May 17, 2002, 1:16am UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/29 "2002-05-17T01:16:57Z")
> [@](#): > > Just another plug for Cryptonomicon. Damn fine read Just don’t use the deck of cards encryption. It is not really secure. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [May 17, 2002, 2:28am UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/30 "2002-05-17T02:28:14Z")
There were actually quite a few lives lost due to commanders _ignoring_ decrypted information. Montgomery is widely reviled for this (and other flaws). Several American admirals in the Pacific also refused to believe such information. Midway was more of an exception than the rule. MacArthur was explicitly told the Japanese were going to attack the PIs and he did zip. On the Russian side, Joe Stalin was so ticked off on the reports of an impending German invasion that he started ordering executions for anyone making such “false” reports. These jerks caused millions of people their lives. ---
**Author:** ![Swede\_Hollow](https://avatars.discourse-cdn.com/v4/letter/s/3bc359/32.png) [@Swede\_Hollow](https://boards.straightdope.com/u/Swede_Hollow)\ **Post date:** [May 17, 2002, 3:20pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/31 "2002-05-17T15:20:51Z")
> [@](#): > > \*Originally posted by ftg \* > **MacArthur was explicitly told the Japanese were going to attack the PIs and he did zip.** Well, not QUITE true. He DID line up all of his airplanes (against the recomendation of EVERY subordinate in his command) in nice neat rows for the Japanese to take out in one quick pass. (He claimed it was to make the planes easier to defend against sabotage). ---
**Author:** ![detop](https://avatars.discourse-cdn.com/v4/letter/d/bcef8e/32.png) [@detop](https://boards.straightdope.com/u/detop)\ **Post date:** [May 17, 2002, 3:31pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/32 "2002-05-17T15:31:22Z")
> [@](#): > > \*Originally posted by Swede Hollow \* > \*\* > Well, not QUITE true. He DID line up all of his airplanes (against the recomendation of EVERY subordinate in his command) in nice neat rows for the Japanese to take out in one quick pass. (He claimed it was to make the planes easier to defend against sabotage). \*\* Actually, no. After receiving reports on the attack on Pearl Harbor (where the planes were lined up to defend against sabotage), he **delayed** attacking the Japanese air bases in the Pescadores and Formosa (which were fogged in at the time) and set up Combat Air Patrol over his fields. Eventually, the fog lifted in Formosa and the Japanese flew in their missions as intended, expecting to be welcomed by a flurry of fighters. Imagine their relief when they found out that the American fighters were mostly on the ground, refueling. ---
**Author:** ![galen](https://avatars.discourse-cdn.com/v4/letter/g/ecc23a/32.png) [@galen](https://boards.straightdope.com/u/galen)\ **Post date:** [May 17, 2002, 3:51pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/33 "2002-05-17T15:51:41Z")
[QUOTE] \*Originally posted by ftg \* Joe Stalin was so ticked off on the reports of an impending German invasion that he started ordering executions for anyone making such “false” reports. QUOTE] Do you have a cite for this? My understanding is that the Soviets were fully informed of the plans for Operation Barbarossa. For a good description of the handling of the intelligence produced by the breaking of the ENIGMA cipher, read “The Ultra Secret” by F. W. Winterbotham. It is out of print, but can be found used at the usual large online bookseller or at a good library. ---
**Author:** ![The\_Peyote\_Coyote](https://avatars.discourse-cdn.com/v4/letter/t/5f8ce5/32.png) [@The\_Peyote\_Coyote](https://boards.straightdope.com/u/The_Peyote_Coyote)\ **Post date:** [May 17, 2002, 5:53pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/34 "2002-05-17T17:53:32Z")
galen: According to Churchill’s six-volume memoris of WW2, both the British and Americans repeatedly warned Stalin of Operation Barbarossa. I’ve read several histories of the war that claimed that Stalin igorned these, and was thus surprised, and others that claim he was, in fact, aware the Germans were going to attack. It’s hard to find the truth when you are dealing with Stalin. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [May 17, 2002, 7:08pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/35 "2002-05-17T19:08:46Z")
Note that I said _Stalin_ didn’t _believe_ the reports. Every other Russian official and officer knew perfectly well it was coming but were helpless to try and prepare for it. ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [May 17, 2002, 8:32pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/36 "2002-05-17T20:32:14Z")
The book _ **A Man Called Intrepid** _ repeats the story of the bombing of Coventry, and states that the British knew the Germans were going to bomb the city and did very little to alert the civilians before the bombing. The book also recounts other instances where the Allies remained quiet about German operations they knew of in advance because they didn’t want to tip the Germans off to the fact that they had cracked Enigma. The reason the book gives is that the Allies felt more lives would be lost if the Germans found out that the Allies had cracked their code and switched to different encryption methods. **Swede Hollow** , your theory might be plausible, but IIRC, the Germans were so confident of the Enigma system that they were transmitting the Enigma settings for the next day in their communications, and the Allies were able to set their machines to the same positions. Had the Germans found out that the Allies had cracked their code, they could have simply announced the setting changes using a different method and it would have taken the Allies some time to figure out what the new settings were. This could have bought the Germans valuable time and lengthened the war, if not significantly altered its outcome. ---
**Author:** ![MonkeyMensch](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@MonkeyMensch](https://boards.straightdope.com/u/MonkeyMensch)\ **Post date:** [May 17, 2002, 9:55pm UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/37 "2002-05-17T21:55:03Z")
Just to put in my bit: A terrific read is Anthony Cave Brown’s _Bodyguard of Lies_. Comprehensive and well written it deals with the use of deception and counter-intelligence in WWII. ---
**Author:** ![bonzer](https://avatars.discourse-cdn.com/v4/letter/b/45deac/32.png) [@bonzer](https://boards.straightdope.com/u/bonzer)\ **Post date:** [May 18, 2002, 1:08am UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/38 "2002-05-18T01:08:43Z")
> [@](#): > > \*Originally posted by London\_Calling \* > I sometimes wonder how much detail the people who were there actually remember (given how eventful was every day) and how much is later presented as historic fact by the interviewers. Difficult to say unless you hear the interviewee’s pauses and “Hmm…” 's Absolutely, though it’s a central part of any historian’s training (not that I’m an historian) to evaluate the limitations and biases of any particular source. In keeping with that, I should say that I don’t regard Jones as having the final word on the issue. He’s the source I happened to have to hand and his memior is undoubtedly one of the key accounts for what happened that night, but, for instance, his adoration of Churchill is too apparent throughout his book for him to be regarded as entirely objective. (FWIW, Christopher Hitchens cites a very different interpretation by David Irvine [spit] in [this recent article](http://www.theatlantic.com/issues/2002/04/hitchens.htm); in it Churchill heads for the Air Ministry roof _because_ he knows from Ultra that London isn’t the target, as piece of safe grandstanding.) However, in this particular case, the paperwork will all survive and I’d expect that it is possible to reconstruct exactly what Churchill did have in the red box in the car, in the same way that historians can establish what was known to the relevant intelligence authorities that day. Presumably Hindsley and Gilbert would be the places to start for the details. **Tuckerfan** : nobody takes _A Man Called Intrepid_ as a reliable source these days, particularly as regards Coventry. It should however be noted that there _were_ occasions where Bletchley and their customers were able to predict targets in advance. (Not to mention the fact that there were plenty of locations which could be guarenteed Luftwaffe bombing raids regardless of Engima.) That Coventry has become the location of the story/myth seems to have far more to do with that raid’s status as the single exceptionally memorable, even symbolic, night. Even allowing for the fact that they failed to identify the target, this aspect also wasn’t foreseeable by the British on the day. The other cases do suggest that, no, an evacuation wouldn’t have been ordered even if the target had been established. But that would have been due to wider attitudes about strategic bombing rather than a specific intention to protect Ultra. Frankly, the “lives sacrificed for intelligence” argument would never have occured to those taking the decisions. Given that cities wouldn’t be evacuated, those involved were doing their best to save lives by using the decripts to jam signals and direct fighters. ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [May 18, 2002, 1:16am UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/39 "2002-05-18T01:16:22Z")
> [@](#): > > \*Originally posted by bonzer \* > \*\* > **Tuckerfan** : nobody takes _A Man Called Intrepid_ as a reliable source these days, particularly as regards Coventry. Really? When did the book acquire its tawdry reputation and how did it do so? I’ve seen nothing that contradicts anything I’ve read in it. ---
**Author:** ![capacitor](https://avatars.discourse-cdn.com/v4/letter/c/e47774/32.png) [@capacitor](https://boards.straightdope.com/u/capacitor)\ **Post date:** [May 18, 2002, 5:16am UTC](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375/40 "2002-05-18T05:16:35Z")
To be fair, the Nazis missed some big ones. They got a report of a secret meeting btween the alliances, to be held in a place listed as _Casablanca_. They thought it meant ‘White House’ and had their spies focused there. Meanwhile the Allies met in Casablanca, Morocco, without a hitch nor their intelligence compromised. [Previous page](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375.md?page=1) [Next page](https://boards.straightdope.com/t/did-the-allies-knowingly-send-men-to-death-to-avoid-revealing-the-cracked-enigma/109375.md?page=3)