WI: Japanese discover Manhattan Project

I know it seems far fetched, but what if by some lucky encounter, Japanese spies in the U.S. discover information about the Manhattan Project? Would it be possible Japan would launch a seaplane raid against the Hanford Site in Washington? Possible attempts at sabotage? Leak information to the Germans?
 
Hanford is too far for a seaplane raid, and there is at least two air bases in Western Washington. That's assuming they got past the air bases in the Seattle area, which for those raiders would be a BIG if. That sort of a raid would be a disaster if it was even attempted.

Japanese Americans were under intense scrutiny during WWII, so sabotage is probably not an option, unless the Japanese are able and willing to employ America spies - and I'd put that under very unlikely. Passing information to the Germans might work, but the Germans would have a bear of a time trying to do anything about it, too.
 
I like the question.

Considering the size of the project it seems quite reasonable for spies to find out about it. Perhaps it the Japanese use hostages from occupied lands, either Asians, or Europeans to recuit non-japanese spies in the US.


I don't see the Japanese being able to do anything about it though. Nothing significant anyway.

But knowing of the ongoing project, and the danger it poses to them could have interesting effects on their actions.

The very least is perhaps a surrender after one bomb.

Perhaps even more agressive attacks on islands in the pacific trying to deny the US airbases.

Perhaps a long term focus on taking Hawaii?

Maybe widespread use of chemical WMDs in an attempt to balance the coming atom bomb?
 
German spies would probabaly be more plausable.

As for what happens, it would depend on when it was discovered and exactly what was discovered. If enough details were gained early enough, Ni-Go and/or F-Go could be accelerated and F-Go's testing an atom bomb at Hungmun might not be a myth. They might have shared the info with the Germans, accelerating the Uranverein project.
 
Japanese Americans were under intense scrutiny during WWII, so sabotage is probably not an option, unless the Japanese are able and willing to employ America spies - and I'd put that under very unlikely.

There's also the fact that no Nissei ever spied for Japan's govt. Even so called Tokyo Rose was mostly a propaganda invention. The woman charged with being her was not guilty and received a rigged trial and later a presidential pardon.

An interesting if unlikely possibility is Elijah Poole AKA Elijah Mohammed, leader of the Nation of Islam, who was a Japanese sympathizer. But I seriously doubt the NOI had the ability to pull sabotage off.
 
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Cook

Banned
Japan’s Unit 731 was involved in extensive testing and limited use of Biological weapons in China.
Had Japan found out about the Manhattan Project they may have threatened to retaliate with Plague warfare or tried for a pre-emptive strike against the East Coast of the United States using Biological agents dispersed from seaplanes launched from submarines.
This wouldn’t have won them the war but many of Japans other plans made no sense at either.
 
I have a feeling that the Germans and Japanese could consider that the A-Bomb is a great reason to use Chem. Warfare. I see a far nastier WWII.
 

Larrikin

Banned
Bio warfare

Japan’s Unit 731 was involved in extensive testing and limited use of Biological weapons in China.
Had Japan found out about the Manhattan Project they may have threatened to retaliate with Plague warfare or tried for a pre-emptive strike against the East Coast of the United States using Biological agents dispersed from seaplanes launched from submarines.
This wouldn’t have won them the war but many of Japans other plans made no sense at either.

The Japanese did in fact launch a plague attack against the USA. They used the same technique as the attempted fire bombing. They launched balloons from submarines into the prevailing airstream, with small timed detonations to pop the balloons and release the bombs.
 
I have a feeling that the Germans and Japanese could consider that the A-Bomb is a great reason to use Chem. Warfare. I see a far nastier WWII.

Japan going biological/chemical on the 48? Jesus H Christ, you won't have Hiroshima and Nagasaki. You'll have Tokyo, Osaka, and Kyoto, and Truman dictating terms from an airfield filled with B-29s.

This is 1940s America, people.
 
Japan going biological/chemical on the 48? Jesus H Christ, you won't have Hiroshima and Nagasaki. You'll have Tokyo, Osaka, and Kyoto, and Truman dictating terms from an airfield filled with B-29s.

This is 1940s America, people.

Hardly. By late 1944, Japan has no ability to launch chem/bio attacks on the 48, or even Hawaii. Even a sub-launched seaplane raid has become impossible in the face of total American control of the Pacific and the air above it. That only leaves the balloon bombs, which were jokes which would and did hit nothing but forest and wilderness. Really, the most likely big change from Japan knowing about the Manhattan Project would be less head in sand insistence that Little Boy wasn't atomic, or was an one-off fluke, and maybe surrender before Fatman gets dropped.
 

Nikephoros

Banned
Japanese Americans were under intense scrutiny during WWII, so sabotage is probably not an option, unless the Japanese are able and willing to employ America spies - and I'd put that under very unlikely.

As you said, they were under intense scrutiny, and I doubt there were any Japanese-American scientists in the project, and if there were, they would be kept from public areas.
 
Hardly. By late 1944, Japan has no ability to launch chem/bio attacks on the 48, or even Hawaii. Even a sub-launched seaplane raid has become impossible in the face of total American control of the Pacific and the air above it. That only leaves the balloon bombs, which were jokes which would and did hit nothing but forest and wilderness. Really, the most likely big change from Japan knowing about the Manhattan Project would be less head in sand insistence that Little Boy wasn't atomic, or was an one-off fluke, and maybe surrender before Fatman gets dropped.

Depends when they find out. I wouldn't put it past the IJN to run some of their I-400s loaded with god-knows-what at Los Angeles in 1943.
 
Depends when they find out. I wouldn't put it past the IJN to run some of their I-400s loaded with god-knows-what at Los Angeles in 1943.

But that would infuriate the American public far worse than Pearl Harbor did, and you'd end up with the public demanding the atom bombing of all of Japan's major cities, not to mention biological warfare from the US. By early 1946, one could conceivably be looking at, to quote Bill Halsey, Japanese quite literally only being spoken in hell.
 
But that would infuriate the American public far worse than Pearl Harbor did, and you'd end up with the public demanding the atom bombing of all of Japan's major cities, not to mention biological warfare from the US. By early 1946, one could conceivably be looking at, to quote Bill Halsey, Japanese quite literally only being spoken in hell.

When has Imperial Japan ever cared about infuriating the American public? It's their whole concept of "hey, they can kill us all, so let's hit them first and scare them because they don't have enough fighting spirit" that we saw in action at Pearl.
 
When has Imperial Japan ever cared about infuriating the American public? It's their whole concept of "hey, they can kill us all, so let's hit them first and scare them because they don't have enough fighting spirit" that we saw in action at Pearl.

True. Note that they did employ bio and chem attacks against Chinese civilians and wanted to employ them against US forces in the Pacific.

If they were to attempt such an attack on the US west coast, I wonder in San Francisco wouldn't have been a better target...

But more important, as I said above, is what information they get and when. If they get certain details in time, F-Go may have gotten underway earlier. If they got enough details and if the IJN was able to push enough resources to Arakatsu, or better (worse, really), a cooperative project with Germany, a crude device might have been available as the ultimate Tokkotai for use against the invasion fleet for Operation Iceberg.

Then you'd really have a bad result for Japan. :(

And combine it with a successful west coast attack like you suggested above... :eek:

Tokyo, Kyoto, and Osaka would be the start...
 
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