The Japanese tried to crack the code by torturing a poor guy called Joe Kieyoomia who was Navajo, but not a code-talker or even aware of the existence of the program, but they didn't get far. Amazingly, he survived the concentration camp, the Bataan death march and getting nuked in Nagasaki, returning to the US and living until 77.
That's kind of interesting because the limited understanding I had based off an interview I watched was the code talkers were not actually using Navajo as some form of steganography. Even a direct translation to Japanese by an expert in both languages would give you a seemingly meaningless sentence. I specifically remember the guy saying "potato" was used to refer to hand grenades for example.
That's why encrypted messages still use code words and code phrases. Although the US did crack the Japanese encryption, the use of code words stymied them. The inference that Midway was the target of the Japanese attack was guesswork on what the code word for Midway was.
Code words and phrases can be cracked once one gets enough context.
More specifically, it was active counter intelligence where the US sent a false report of a water issue on Midway broadcast in the clear that they then picked up the Japanese report of the issue. They used that to discern which codeword Japan used for Midway.
You're right, but it was still scant information with which to bet the fleet on. The Japanese might have suspected that their code was broken, and so used disinformation to mislead the US Navy.
Hell, it's what I would have done whether I thought the code was broken or not.
The Germans had plenty of evidence that Enigma was broken. The High Command refused to believe it. I would have used the broken Enigma to send the Allies into a trap.
The way to play the code breaking game is to assume the enemy has broken it, and act accordingly to your own advantage.
Even if you know one of your widely-used codes or cyphers has been broken, I don't think it is that easy to make use of that fact, except perhaps briefly and in a limited way.
To conceal the fact that you know that it is broken, you would need to maintain use of that code at similar levels as before, without approximately doubling the signal traffic by sending the real communication under a new code. Furthermore, the fake traffic under the original code must be realistic to the degree the enemy can verify it, as they can read it, and if a major code has been broken for a period of a few weeks or so, the enemy presumably has plenty of information to use in verifying new messages, at least for a while (the verification need not be explicitly performed, at first; if new messages seem to be inconsistent with what is already known, questions are likely to be raised.)
Compromised minor cyphers and codes are another matter, and that is exactly how the Midway ruse worked.
For Nazi Germany the "fake traffic" would not be needed for all the services. Key change happened at midnight Berlin time by all operators. The radio operators stayed up late into the night sending the personal correspondence of the various officers to their families. The codebreaking process used this huge volume of messages to feed into the "cribbing" process which aided in recovering the traffic. By the time they had extracted enough of the key to decrypt traffic, normal military communications had started
Correction: I wrote ‘without approximately doubling…’ where I meant ‘while approximately doubling…’ - and then one must take into account sidewndr46’s interesting point.
How do you keep your allies from believing your fake encoded messages and taking the same action that they would have taken, had you not suspected the code was broken?
There was a lot of this. The Enigma cracking team would use things like weather reports and convoy sightings as known plaintext for their work. If you pick up a submarine transmitting near a convoy, it’s probably saying that it saw a convoy at such and such coordinates. The same key was reused for the other messages from that day so cracking one let you read them all.
If I was running it and transmitting coordinates, I'd give the U-Boot commanders one-time pads to obfuscate them, and then encrypt the entire message.
> The same key was reused for the other messages from that day so cracking one let you read them all.
I know. The Germans were simply idiots in their hubris about Enigma. The evidence it was cracked was overwhelming, but Doenitz just dismissed it all. Rommel was also defeated by decoded Enigma messages, and he dismissed all evidence of its subversion.
The weird thing is that it's possible the Enigma could have been used during WWII for communications. With the right number of rotors, the right choice of keys, and the right key rotation schedule it is possible.
Of course when you believe you are in the most advanced nation in the US, what is the incentive to improve?
I wonder how hard it would have been to provision each submarine with enough one-time pad to cover all secure communication for their entire patrol. I don’t know how much radio traffic there was, but it seems like that would not have been a major burden.
Hand them a newspaper. Plenty of text there to use as a pad. The code breakers would need to know both the newspaper used, and the algorithm used to select letters from the paper in order to crack it. Or use a magazine to provide the algorithm.
Every U-Boot mission gets another newspaper. Every U-Boot has a different newspaper. There weren't that many U-Boots, so this would be manageable.
Even decoding one U-Boot's transmissions would not compromise the others.
The U-Boats have plenty of other operational failures. Whenever U-Boats would be potentially damaged by the Allies, they'd put a notice in at one of the British listening stations. When the U-boat came into port, it'd radio in advance that it was damaged and might need special provisions (couldn't steer well, etc.) or even a tug to make it into the harbor. This all happened in German on the HF radio, which propagates really well. At least to Britain and possibly all the way to the mainland US.
The Allies basically got free reports of exact damage they inflicted on subs this way. On the other hand if a report didn't show up in a few days, they probably sunk it.
That's exactly why they didn't get anywhere. Per the Reddit thread below, Joe was able to understand phrases like "red soil ahead", but that was not enough to work out the meaning.
It is interesting then because it shows how laughably ineffective the actions of the Japanese were in World War II. All they needed to do was have Joe do transliteration, then pass the results to intelligence analysts. It would have yielded something, albeit likely limited
It's worth noting just how extreme the levels of crime against humanity committed by the Japanese were.
The Germans (and Swiss...) for the most part imprisoned / shot PoWs.
The Japanese used PoWs for chemical and biological weapon testing and vivisection, and they would find the most depraved ways to draw out mass torture of PoWs.
For example, they would do things like put US soldiers into baskets so small PoWs could not move at all inside them, load them into unventilated railroad boxcars with no water, then load them into ships, sail out to sea, and drop them overboard into shark-infested waters.
Then there's the Nanjing Massacre where in a matter of days Japanese soldiers slaughtered something like 300,000 Chinese civilians at a rate of around 7,000 civilians a day. That was just one of the more than a dozen massacres. It's widely believed that Japan slaughtered more civilians than the Germans.
The sheer level of depravity is astounding. And what's especially disturbing are the lengths conservatives in the Japanese government have gone to over the last several decades to rewrite history and erase these atrocities, while pushing harder and harder against the restrictions on their armed forces.
from a warfare perspective, this is really bad strategy. it strikes fear into your enemies, but it's massively outweighed by making your enemies fight to the absolute last to not be captured
It was deeply ingrained by their internecine conflicts. When factions would fight in their internal wars, they would expect the losing side to commit suicide if they happened to be defeated and not dead by enemy hands. Their military class was not introspective enough to consider that implication of this, if applied to its logical end in a conflict with an out-group, would be the total extinction of their ethnic group.
It's pretty classic in-group / out-group conditioning. In fact, incentivizing your enemies to also commit their own atrocities incentivizes your own to fight to the absolute last. The depravity and feedback loop is intentional for these kinds of extremely ideologically motivation groups.
Indeed. Modern warriors understand this concept. This is why Al-Julani of HTS (the group that has prevailed in Syria) has emphasized that he supports 'diversity' and that the Kurds and so on will be recognized. There were various forces at play in Syria and he'd be in a war with all of them if he was hardline right at the start. The constraints of peace apply to all, violent or not, and to win it's better to not be religious about your violence.
The idea was that the Japanese soldiers would see the atrocious that they were doing, realize that the Americans would want revenge, so the Japanese better fight to the death, since that's better than what the Americans would do to them in captivity.
It ends up that the Americans weren't too in to revenge, so the captured Japanese were surprised.
Japanese soldiers fought to the death because they knew that their families would be punished if they didn't.
In Japanese culture at the time the sins of the father are inherited by the sons and daughters.
If you surrendered you would be dooming your entire family to a life of poverty and shame. To most decent people that would be worse than death.
And even before that, burned > 500 square miles of Japanese urban areas to ash.
Granted, by the last weeks of the war, the USAAF was dropping leaflets warning they'd be back with incendiaries in a few days, a masterstroke in psychological warfare.
Hot take, but Japanese civilians (all civilians, not just men) were to fight American soldiers if they invaded Japan. We'll never know what would have happened if America invaded, but Japan certainly was not making civilian evacuation plans. So maybe innocent-ish civilians?
Many wars would be cut short if the winning side offered amnesty. I suspect that Germany would have surrendered a year earlier if the Allies had offered some version of amnesty rather than unconditional surrender.
The Nazis fought to the bitter end because they knew that unconditional surrender meant there would be hell to pay. And there was.
You run the risk of the old regime continuing in some form and a repeat in a decade of the same war. Germany surrender in The Great War and the world was back at it again 15 years later.
This played a big part in the attitude of do it right this time.
So many people died... yet, people are still voting for the AfD, and the idea of the Final Solution[0] is still somewhat alive under the Master Plan name[1]. I love Germany, but as a migrant living here, this is a "bit" uncomfortable. I lived here 15 years and paid more than a million in taxes, then suddenly a "Start Remigration Now" poster appears[2]. Not cool.
> and the idea of the Final Solution[0] is still somewhat alive under the Master Plan name[1].
Sorry, but that's utter bullshit. Also, I wonder how you feel about Turkey's plans to remigrate Syrian refugees back to Syria now that Assad has been deposed.
No that's just a fact. It's the same ideology, trying to be sold under "more acceptable" terms. The BS part is people trying to make it sound milder than what it is. It even wants to deport German citizens who they claim to not have integrated well. More details on similarities: https://www.socialeurope.eu/when-never-again-becomes-again-a...
I don't support any forced relocation of groups of people and find even very long prison sentences debatable. I'm also a big proponent of forcing Turkey to recognize the Armenian and other genocides. Nice try to poison the well though.
People build their lives somewhere, relocating them usually means many steps back. If you ever migrated into a complete new country with different values and language, you would understand.
Have you missed the last ten years worth of radicalization in the AfD? They started out as what appeared to be a relatively normal fringe party under Lucke, and then over the years the far-right managed to shed ever more layers of the onion.
Particularly Höcke, a man who you can legally call a fascist, gives me the chills. And the party youth manages to be even more radical than him, enough to scare the adults into attempting to clean up shop before the youth organization gets banned.
None of the leaders of Germany in WWI were still in power by the time WWII started.
The exact opposite lesson was in fact learned by the Allies from WWI: instead of crippling Germany and the other Axis powers like the French did after WWI, they went with the Marshall plan, rebuilding their economies and making sure they have an actual future.
The Kaiser wasn't the problem after WWI, it was poverty that allowed the Nazis to rise to power.
After Germany surrendered and the war in Europe was over, America began systematically dismantling West Germany's industrial capabilities. No aid was to be given save the absolute minimum needed to prevent starvation, all the work of rebuilding Germany was to be left to the Germans. The Red Cross was forbidden to visit allied camps of German POWs to provide food or aid. It was even forbidden for Americans to send packages of food to Germans.
Over the next two or three years these orders were one-by-one rescinded and reversed, mostly for national security reasons when the Soviet threat was acknowledged and Germany's role in countering that Soviet threat was understood. But even then, in the end only a small portion of the Marshall plan went to West Germany. Most of it went to the rest of western Europe.
>None of the leaders of Germany in WWI were still in power by the time WWII started.
This isn't really true. Hindenburg was instrumental in Hitler's rise to power. Ludendorff was the de facto dictator during WWI and proceeded to create the stab-in-the-back myth and to fight for the Nazis. There is absolutely lots of continuity between the WWI regime and the Nazis.
Hardly. A handful of very high ranking Nazis were tried and hanged. Many of them escaped via ratlines. Nearly all the mid-level officers and civil authorities escaped any sort of punishment or justice, and continued happily serving in the West German state.
A handful of very high ranking Nazis were tried and hanged.
This is a misconception. As a result of the "Nuremberg Trials" which concluded in 1946 and focused specifically on high-level defendants, 11 people were hanged. But there were numerous other trials, including what were called the "Nuremberg Military Tribunals" from 1946-1949, the Bergen-Belsen trials, and so on, as a result of which scores of people of decidedly lesser status were executed, easily some 200+.
Nearly all the mid-level officers and civil authorities escaped any sort of punishment or justice, and continued happily serving in the West German state.
An amnesty for what, mass murder, a policy of multiple genocides?
Also the Nazis claimed the German army was not losing WW1, but were betrayed by politicians. Perhaps WW2 would not have started if WW1 ended in unconditionally surrender?
Also worth noting that along with Operation Paperclip, where the US recruited Nazis to bootstrap their space program, the US also recruited Japanese war criminals to continue their experimentation in torture and chemical and biological warfare, which led to (among other things) MKULTRA.
And in Bluebird and Artichoke the US directly continued that work, and not in some kind of "generic spirit" way, but in literal extensions of existing programs using people gathered via Paperclip. And in Korea the US used bioweapons developed by the Japanese during a retreat in late 1952.
The Japanese were indeed horrible during the war. The take that the Germans and the US treatment of "expendable" humans during and after these wars was somehow more justified or less horrific is a uniquely horrible and ahistorical take.
Mostly pilots of planes that ended up in Switzerland. Without GPS or mid-air refueling that did happen a lot. Swiss neutrality meant shooting at any military that entered their territory, no matter which side they were on, and taking anyone who surrendered captive.
Anything else could be seen as helping one side or the other, which wouldn't be very neutral. Not that they were always above helping them in non-military ways
I don't think they "shot the PoW", and I don't even know if they emprisoned them. Feels very weird how the original comment put it (why link the Swiss to the Germans like this?).
But I know that German planes ended up in the Swiss airspace. The Swiss told them to land (like "we will now escort you and you will land on our soil, and if you don't comply we shoot you down"). They refused and got shot down.
But it's very different from shooting a pilot that would be in a state of PoW.
I seem to remember that navigation systems existed during WWII for both taking bearings and computing your actual location, albeit in a wide margin of error. The British apparently jammed some well enough that Nazi pilots just landed somewhere in the Northern part of the UK
Dead reckoning while flying is hard even today. If you are flying under IMC (instrument meteorological conditions, pilot slang for "bad weather/can't see shit"), you generally have to trust that your meters and instruments are working. Without GPS (or ground based triangulation methods), you generally have to guess where you are. It's very easy to accidentally end up in a small country like Switzerland.
If anyone's looking to build a startup in aviation, try building an alternative to pitot tubes. It's pretty much the last remaining vacuum instrument that hasn't been replaced by a solid state/MEMS alternative. And vacuum instruments are about as reliable as Windows Vista.
>> It's worth noting just how extreme the levels of crime against humanity committed by the Japanese were.
>> The Germans (and Swiss...) for the most part imprisoned / shot PoWs.
Not to take anything away from the Japanese, and the Soviets, who were also horrible to POWs, but I'm pretty sure that the WWII Germans are charter members of the Hall of Fame for crime against humanity. They just didn't do most of it specifically to POWs.
(And if you want a good history of horror in broadly-speaking early-middle 20th century Eastern Europe, I suggest reading Bloodlands by Timothy Snyder.)
Not to take away from the depravity of Japanese violence in WWII, but 300,000/7,000≈43. The rate was either higher, or “a matter of days” is probably the wrong term.
> And what's especially disturbing are the lengths conservatives in the Japanese government have gone to over the last several decades to rewrite history and erase these atrocities, while pushing harder and harder against the restrictions on their armed forces.
This is still a hot issue in Japanese Buddhism and demonstrates the difference between the sects:
Consider Soto and Rinzai Zen, vs Jodo Shinshu. Leaders from both supported the war efforts and nationalism, but since Soto and Rinzai teachers are supposed to be enlightened, the Soto and Rinzai authorities have not been able to apologise for their support. On the other hand, since in Jodo Shinshu everyone, including the head of the school (monshu), is on the same spiritual level (there is no attainment in Jodo Shinshu), they were easily able to apologise for the acts and ideas of the WW2 monshu.
There seems to be 29 original code talkers who were primary in the development and then the program expanded. The 2014 article is on one of the original 29.
If anyone is passing through Kayenta, AZ (very close to Monument Valley) there's a free small exhibit about the Navajo code talkers. Strangely enough, it's inside a Burger King of all places. Atlas Obscura features a brief article about the display:
I just visited Monument Valley and it was spectacular. Inside the Visitor Center they have a whole room devoted to the Navajo code talkers. I only spent a few minutes in it but it was very interesting and very nicely presented.
Strange obituary where the writer do not even mention his real name, Hash-keh Nah-adah, as opposed to the english name that he was forced to use at school years later.
It has twice been proposed in the Navajo Nation Council to officially change the name from Navajo to Dine and both times the proposal was voted down. This was largely because the proposal was unpopular among members of the tribe. There are multiple generations that have grown up being Navajo, they think of themselves as Navajo, and they want to continue to be referred to as Navajo.
Also, growing up (white) on the Navajo reservation, I was taught that Dine was the native language word for themselves, but no one ever expressed any desire for white folks to refer to them as Dine. They tended be private about their culture - there were aspects that were for them not for us, sometimes plainly and other times more subtly. Dine sometimes had that feel, like it was a private name amongst themselves, not a public name for outsiders to use. In other ways it was similar to German vs Deutsch, just a different word in a different language.
It is more recently that some Dine activists have cast off the name Navajo as colonial and wish to be referred to as Dine, but as far as I can tell it still isn't the majority opinion.
There have been successful cases like this though. The Ho-Chunk of Wisconsin, more popularly known as the Winnebago (which is what a neighboring tribe called them), officially changed their name to Ho-Chunk (which is what they call themselves) in 1994. Part of this is also probably because that most people associate the name "Winnebago" with the RV brand rather than a people.
Bizarrely, Germans call themselves Deutsche and the Dutch call themselves all sorts of crazy things. Swiss, Spanish, oh the whole of Europe.
As for Japanese, Chinese, Russia ... errm most of the rest of the world 8)
In English we don't really get America(n) "right", and they are one of the larger populations that speak the bloody lingo! Oh and lingo: lingua - Latin with a twist, that's how we Anglo-Saxons keep it real!
"The Navajo are speakers of a Na-Dené Southern Athabaskan language which they call Diné bizaad (lit. 'People's language'). The term Navajo comes from Spanish missionaries and historians who referred to the Pueblo Indians through this term, although they referred to themselves as the Diné, meaning '(the) people'."
English speakers don't call anyone by their own name. "Japan" is another good example here.
Interestingly, the Japanese term for other countries/languages are frequently much closer than the English versions. So while English speakers call the Deutsch "German" and Deutschland "Germany", Japanese speakers call them "doitsu", which is just as close as you can transliterate "Deutsch" to the syllables allowed in Japanese. It's not a rule though: the proper term for the USA is "beikoku", which translates to "country of rice". (The colloquial term for USA however is "amerika", which is exactly what Americans call themselves colloquially.)
> The colloquial term for USA however is "amerika", which is exactly what Americans call themselves colloquially.
This reminds me of something I was thinking about recently.
I started noticing a few years ago, when I began listening to a lot of podcasts made in the UK, that there's a gap between how Americans colloquially refer to ourselves and how the rest of the world does. The upshot is that the term "America" is used much more liberally overseas. For example, journalists overseas will often use "America" and "American" even when referring to our institutions, cities/states, and leaders, whereas domestically we will switch to "the US" or "the United States" in those situations. Put another way, domestically we usually say "America" when referring to our national and cultural identity, but often (but not always) use The US or The United States when referring to our country. I'm an American, but I live in the United States. Anthony Blinken is the US Secretary of State (foreigners will say American Secretary of State). Britain's ally in WW2 was the United States, and they were glad when the Americans showed up to fight. Gavin Newsom is the governor of the US State of California. If I return from 6 months abroad, I might say "Gd bless America" after my first bite of real cheeseburger. We'll chant USA! USA! at the Olympics and make an impassioned argument that American cars are the finest in the world. And so on.
Japan is roughly as close to Nippon as doitsu is to Deutsch.
The Germans are somewhat extreme on the exonymic spectrum, there are something like six distinct terms used in Europe for them. I've never heard one complain about it.
"The English word for Japan came to the West from early trade routes. The early Mandarin Chinese or possibly Wu Chinese word for Japan was recorded by Marco Polo as Cipangu. The Malay and Indonesian words Jepang, Jipang, and Jepun were borrowed from non-Mandarin Chinese languages, and this Malay word was encountered by Portuguese traders in Malacca in the 16th century. It is thought the Portuguese traders were the first to bring the word to Europe. It was first recorded in English in 1577 spelled Giapan."
> Marco Polo called Japan 'Cipangu' around 1300, based on the Chinese name,[6] probably 日本國; 'sun source country' (compare modern Min Nan pronunciation ji̍t pún kok).
The pronunciation "Japan" is from Chinese (or, to be pedantic, some Chinese language) pronunciation of 日本, which is pronounced as Nippon in Japan. It happened because the Chinese character 日 ("sun") has widely different sounds in modern languages. Probably it had an unusual sound in the old time.
Yes, the name is a corruption of a Chinese name for Japan. So what's your point? Japanese is not the same language as Chinese; it isn't even related linguistically other than borrowing part of its writing system.
It's basically like making up a name for the UK based on a corruption of what the Romans called it 2000 years ago, and then trying to claim this is similar to what Britons call it today.
1) The sense and importance of community. Both the mention of them coming together when he returned where "the ghosts will be laid". And also the mention of "there was no “I” in his war, only “we”. We're stuck in such an individualist culture where we're told to work hard to stand out, and seem to be shamed if we're weak and in receiving help from others.
2) Words as metaphors. Beautiful examples given in the post, but we should remember the roots of many of our words are also metaphors. My favorite being "persona"[0], coming referring to an actors mask that air goes through. Helps remind me that we're always actors in the world, not some defined Self we're stuck with. Good book[1] on that topic from Jay Garfield.
3) Explanation at the end of his "Navajo Code-Talkers uniform". Mentions that yes, it's more than ok to imagine clothes as images and have meaning beyond "something to wear for efficiency". The Emerald podcast talks about these things, both ornaments in general from human history [2] and more specifically about guardians [3] which is what he considered the Navajo colors were for, to protect him.
The similarity of all these cases, to me, comes to they're not all thoughts he had in his head as words, which is what we're told to do from the smallest of ages. We're told to think hard, and use words (like I'm doing here) to be smarter than others. When looked at, words and thoughts are nothing compared to the experienced feelings that come from community, imaginal metaphors like hopping rabbits that leave tracks in the snow, or looking at colors you're wearing and feeling protected.
I've always wondered why the Japanese didn't do the same thing in reverse. There's gotta be some tiny languages from small ethnic groups on the islands. At the time, it's not like we could have gone and looked up the words in a dictionary somehow. Even without it being encoded, it would have worked pretty well. And yet they didn't even think about it, as far as I know.
Japan is (and was) a pretty ethnically homogeneous place; the largest indigenous minorities are the Ryukyuans and the Ainu. The Ryukyuan languages aren't all that different from Japanese in the first place, and the Ainu were subjected to forced assimilation that has made many ethnic Ainu unable to speak the language, and while I'm not sure of the speaker count in the 1940s, I doubt it was that high. While their imperial possessions at the time would have included lots of other ethnicities, incorporating Korean or Chinese code talkers wouldn't have been that helpful (not that hard to find people who speak those languages), and the size of their Pacific Island groups would have likely struggled to produce enough adequate code talkers. Although the institutional racism of the country was probably enough to forestall any plans in the first place.
It's also worth pointing out why the use of Navajo code talkers was so successful. Part of that is that it's from a language family that was poorly known by linguists at the time. But even within that language family, Navajo is pretty different (compare how different English is from other Germanic languages, or indeed most Indo-European languages). It's also a fiendishly complex language; like, there's no regular verbs--that would make attempts to crack it via standard cryptanalytic techniques rather more difficult. (Also worth pointing out, it was a code within Navajo so that even when the Japanese pressed a Navajo POW into translating the messages, they couldn't crack it).
Apparently they did: I've heard it claimed there was at least one submarine that used Kagoshima-ben, a famously impenetrable dialect spoken in southern Kyushu, for precisely this purpose. I can't find any reliable source though.
More generally though, Japan now and Imperial Japan in particular was very big on there being "one Japan" with one Japanese people and one standard language. Dialects were not encouraged and Okinawan, which is really a different language, was ruthlessly suppressed (kids punished for speaking it in school etc).
Those letters mean: "Welsh not". Back in the day, Welsh children would be punished for speaking Welsh (instead of English) and made to wear a wooden board with WN on it around their neck. The board would be passed on through the day to the final transgressor who would receive a thrashing or similar punishment. Generally all of them would get a thrashing anyway - it was good for them!
Edit: Not, not no ie WN: "Welsh not". Small but important difference.
Context is an interesting key here, I think. That point in the US coincided with a increased interest in First Nations, and in some places a renewed attempt to preserve their heritages, especially linguistically. The US generally sees itself as a nation of immigrants and one axis of its "Freedom of Speech" has historically seen the usefulness to speak one's own language, whatever it may be. Diversity of languages has been a goal for the US at various times in its cultural history. In that context, "what's the most diverse language that Americans speak?" is a question you can ask, and an answer you can find without much difficulty.
Japan had one and only one national language. Japan didn't have the culture of thinking of itself as a melting pot where many languages might meet. It probably wouldn't have thought to ask that question at all "what's the most diverse language that the Japanese speak?" In practice, we can assume that's also why it confused the Japanese for so long in the war, it wasn't a question to think of themselves, it probably was a hard question to ask of Americans if they saw "English" as the national language they might also not think to ask "what other languages do Americans speak?" or maybe even "why isn't this English or a derivative of/code for English?"
While Japan indeed has only one national language, in practice it has many different dialects of that language which are not very mutually intelligible. I live here, any my girlfriend says she can't understand lots of people from various more-remote places. She can't even understand people from the opposite side of her own prefecture. So people frequently have to switch to the standard "Tokyo dialect" when talking to people from other parts of the country. Of course, this is probably lessening over time with mass communications, similar to how Americans largely speak with a "midwestern" or "Chicago" dialect used commonly on TV.
Oh no it's very hard. You go to NYC and spend weeks in barber shops and ethnic restaurants until you hear the fragments of the nearly extinct tongue. Name the language and it is likely spoken in the five boroughs.
A buddy from Latin America who barely spoke English moves to the US. Specifically, he moves to Bushwick, Brooklyn, NYC. He goes, "They all say, 'You gotta learn English. This is America!' but I can't understand any of them - even the Puerto Ricans." First thought in my head was 'dude, you're learning English on hard mode'.
Ranking individual things as more or less diverse than other things is a gross abuse of the concept of diversity anyway. But yeah cataloging the set languages spoken in the US is likely impossible in any meaningful way.
There is a small population of Ainu living in far east of modern Russia. This can be probably extrapolated to them living there during USSR times. Ainu have had... strained relationship with Japan, so they could had been enlisted by the USSR during the war to decrypt messages. That's not to say that Ainu people's relationship with USSR has been ideal either, but them serving as translators during the war seems plausible.
There were footnotes I've seen on Navajo topics that they tried Satsuma(Kagoshima) dialect for the same purpose, but there were no shortages of speakers at the Allied side and the use ended quickly.
Uniqueness of Navajo and other Native American languages was that they were all complete multi millennia isolate from English thanks to how USA came to be. Japan wasn't like that so dialects aren't divergent enough for this use case. Ainu might be a candidate but it's way too high profile.
For this to work, x=D(E(x)) must hold, where x is the message in military English, and E and D are the encoding and decoding functions. Ergo, the Navajo language must have as many possible utterances as military English does. This is neither surprising nor interesting. What is interesting is that E and D were not known by the Germans and could not be effectively reverse engineered in time.
In WW2 there was a lot of panic about "fifth column" infiltration from German special forces. So they came up with a code word that only native speakers can pronounce: Scheveningen.
It's too bad there were never any good movies made about the code-talkers. There was one movie by John Woo, starring Nicholas Cage, named "Windtalkers", but it was terrible; coincidentally, I was just reading an article this morning about the "worst war movies of the last 25 years" and Windtalkers was on it, alongside "Jarhead 2" and others.
