What Would Japan Look Like Post-WWII Land Invasion?

Let's operate off of the assumption that not deploying nuclear weapons against Imperial Japan at the end of WWII would have necessitated either an amphibious invasion or a long and costly blockade/conventional bombing campaign to force their surrender, which I understand to be the assumption that most academics that study that period share.

Presuming that the Allied forces opt for an amphibious invasion, let's disregard the greater geopolitical ramifications that such an operation would cause. Instead, I'm more interested as to the effect that an amphibious invasion likely several scales larger than Overlord would have on the nation of Japan.

Would it be a combined American and Soviet invasion, or just American? If the former, would we see the islands split in to a la Vietnam, Germany, or Korea?

How harshly would the Allied forces punish Japan after a likely bloody victory by amphibious invasion? Would they completely demolish the Imperial system, and force pure Republicanism on the Japanese?

What kind of environmental destruction could be anticipated? Would the entire Japanese countryside - that OTL provides picturesque scenes of centuries old traditional Japanese houses - be charred rubble by the end? Would Hokkaido manage to go untouched, or would there be some sort of grand, Republic of Ezo-style last stand on that (relatively) isolated island? Would major cities like Tokyo, Osaka, and Kyoto end up in a similar state to Hiroshima and Nagasaki in OTL, just completely flattened and burned to the ground - more than those former cities were in OTL, anyways?

How many civilian casualties can we expect? I've heard about plans for mass suicides and kamikaze/banzai charges by civilians, but I don't know how grounded in reality those are. My understanding of pre-WWII Japanese population figures is that they were around roughly one hundred million. How low could we see that drop after an amphibious invasion? Can we expect Soviet Union-tier civilian casualties, with 10%+ of the pre-WWII population being killed? Maybe more? 20%+, even?

OTL, occupying American forces managed to prevent large-scale war crimes in Japan (though there were, obviously, plenty of incidences on a smaller scale) but could we see more incidences of human rights abuses by American and possibly Soviet soldiers on the Japanese civilians, especially if the latter put up significant resistance to the invaders, a la the Vietnamese in the Indochina Wars?

Speaking of resistance, how long/to what degree could we see a resistance movement after the initial invasion is said and done with? Presuming that there are plenty of Japanese soldiers and militants pragmatic enough to not charge gloriously into American/Soviet machine gun fire, could we see a Japanese resistance movement against Allied occupation and a future Allied-controlled government for years to come, a la the plans for the German Werwolf program?

Thanks for any opinions or ideas you have to offer!
 
IN the event of a mainland invasion

If the Japanese know its coming to some degree, they could reinforce the islands some, however since by this stage the islands will basically be quarantined, it wont be too much.

Massive bombing campaigns would take place, and yes most of the cities would be flattened. Also the Soviets don't have any amphibious capabilities, so I could see them getting a more free hand in northern china.
no atom bomb, but if the Japanese use chemical weapons to stall the advance the allies will reciprocate. The Navy is going to sit off shore shelling the island for months and blockading supplies, The Airforce is going to bomb things over and over.

Granted there will be suicides, banzi attacks and other last ditched efforts, but I just dont think Japan would last long once the invasion began and beach heads were established. the war is over at this point. I honestly think they would capitulate at this point. They know they can not stop them and if the soviets are marching in Asia its pretty much just over.

Once ashore there wont be much that Japanese can do to stop things, it would be barbaric no doubt, with the USA more upset that they wont just surrender. Macarthur would get to preside over a shell of what was once Japan

the even worse assumption would be if atomic bombs were/are deployed .. Hiroshima, Nagasaki, and other cities would disappear in quick strikes while the air force continues conventional bombing as well there was talk of hitting the beaches, and also some talk of anthrax.

Population wise, disease and starvation is going to take a toll as well as losses in battle. so you could get your 10-15% number
 
1. The USAAF will bomb smaller and smaller cities and towns until the presence of 3 houses at a crossroads will draw a B-29 raid. Kyushu will also draw lots of raids by medium bombers. The railroad network will be reduced to nothing but downed bridges and twisted rails.
2. Everything within range of naval gunfire will go away, at least of the Pacific side of Japanese Islands - it is unclear if you'll see USN units in the Sea of Japan other than subs and lighter units. Naval aviation will have a field day.
3. When an invasion happens, basically every where where combat occurs and perhaps 20 miles further back will be a wasteland. Every structure will be a target, expect the Japanese to use any and everything as a potential strongpoint so ancient temples, castles, etc will become rubble.
4. If the Japanese use chemical weapons, and it was expected they would, the US will retaliate massively. What would be used will leave areas that will be contaminated for some time to come.
5. The civilian population will suffer severely. Food will be reserved for the military and essential workers, most Japanese will gradually starve. Casualties from the pre-invasion attacks will be severe. When a landing occurs any civilians in the area will be used for militia and be worse than cannon fodder, and the US forces, after a few suicide attacks by civilians, will shoot first and ask questions later even with children. If gas is used by both sides, civilian casualties will be huge as they have no protection.
6. IMHO the Soviets really can't land in Hokkaido before spring, 1946. They don't have the capabilities and the weather beginning in the fall is very bad for this. Even an attack in 1946 would require more US LL for amphibious operations, and given between August, 1945 and spring, 1946 the US and Uk are becoming disenchanted with Soviet actions in Europe...

Bottom line, every day that the war goes on beyond August, 1945, the more the destruction will be in Japan and the more civilian casualties. If it develops in to Olympic AND Coronet, the word apocalypse for Japan will be very mild.
 
It's possible the Soviets might get involved (they had comparatively limited Naval lift and their participation would probably be dependent on Stalin's mood and the attitudes of the Western Allies), chances are though their efforts will mostly be dedicated to driving the Japanese from the mainland while the WAllies foot the butchers bill (smart option probably).

Allied invasions would be very bloody. Expect millions of Japanese casualties from combat, famine and disease. Four horseman style shit across the entirety of the home islands.

The aftermath is going to be bleak. Japan would probably not recover anywhere close to how it did in OTL for a while.
 
Japan would probably not recover anywhere close to how it did in OTL for a while.

Hmm. That brings up an interesting question: To what degree would American material and financial resources go into helping Japan's reconstruction? Would it be more than OTL, to scale with the amount of destruction, or would it be less than OTL, because of potentially greater American animosity towards the Japanese post-invasion?

Also, on a completely different note: Does anybody know how the Japanese reacted to American soldiers landing and occupying their nation in OTL? In Germany I imagine things would have happened so fast that nobody could notice the breakline between "war" and "occupation", but I'm curious as to how the average Japanese civilian reacted to foreign troops suddenly on their soil acting as occupiers.
 
...Would it be a combined American and Soviet invasion, or just American? If the former, would we see the islands split in to a la Vietnam, Germany, or Korea?...
Thanks for any opinions or ideas you have to offer!
Even assuming Churchill loses the 1945 general election, as he did in the Original Timeline, I think the UK is by that point sufficiently committed that the Attlee government will offer to be there alongside the USA and the USA (to reduce the burdens placed on its own troops) will accept.
It might be interesting to consider whether Attlee will offer a coalition government in the UK, with the war carrying on though?
 
If the land invasions was required, then the British might save a little more face as they will come and liberate theirs and France's colonies in SE Asia. What impact this will have is questionable, the most immediate will most likely be a morale boost and what scraps of prestige they can get from their erstwhile colonies and dominions.
 
OTL the Japanese were told by the Imperial Throne to cooperate with the Americans, and they did. In this scenario a lot depends upon how the war ends - if the Emperor says lay down arms and cooperate, the mass of the Japanese will.
 
You know, if only someone had written a story on here which later got published. Eh, @The Red ? ;)

Mind you the OP states that no nuclear weapons are used so things might be a bit better than they ended up in Decisive Darkness, at least in the sense that Japanese society might not have completely fallen apart by the end.
 
The number of strategic targets for the atomic bomb in August, 1945 were quite limited. Once you take out Hiroshima, Nagasaki, Kokura and assuming you keep Kyoto off the list, what is left worth an atomic weapon that hasn't already been razed by conventional weapons. Not much, and regular raids can finish off the burning of remnants pretty easily. Using nukes as tactical weapons, which was considered for the invasion beaches, won't really contribute to the overall destruction of Japan in this scenario. IMHO the only way that any realistic use of nukes would make a significant contribution to apocalyptic Japan would be if the USA was foolish enough to use the Imperial Palace as ground zero, assuming the Emperor was there. This sort of decapitation, especially in the Japan of 1945, would ensure that you'd have Japanese in Japan and elsewhere throughout the Asia/Pacific area fighting on, probably to the death. Even assuming the young prince survives with a regency, the authority of a minor prince and a regent would not be the same.

The longer the war goes on, the more death and destruction in Japan both human and physical. Additionally, the longer the war goes on the more Americans (and others) will die, you'll see the atrocities increase, execution of allied POWs (and interned civilians), and continuing shortages on the US home front. All of this will combine to increase ill will towards postwar Japan with more families experiencing the death or mutilation of their loved ones, often in brutal circumstances. I doubt the US willingness to help rebuild Japan will be as much as OTL, which will combine with the greater death and destruction to make Japan a horror for a very long time.
 
US bomber fleet's range and capability is about to drastically increase as well. The massive B-36 might be pushed out even quicker than OTL (1948) and even then it was rushed in an attempt to use it against Japanese targets in the the Pacific theather. While it was quickly obsolete against the USSR jet aircraft, a blockaded and economically ruined Japan wouldn't be able to have the same effectiveness against it, so you could have pretty continuous high payload bombing runs from Hawaii and back in this scenario.
 
On Okinawa nearly half the population was killed during the battle. Obviously, it wouldn't hit Japan nearly that bad ITTL, but imo it isn't unreasonable to expect upwards of at least 30%, assuming Japan never capitulated and they fought to the end. As for war crimes, it would just be one giant war crime. The Japanese never surrender attitude would certainly not endear the civilian population and POWs to the average G.I. It would be extremely bloody.
 
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