US casualties/deaths if Operation Downfall occurred?

Number of US deaths if Operation Downfall occurred?

  • 100,000 deaths

    Votes: 4 13.8%
  • 200,000 deaths

    Votes: 1 3.4%
  • 300,000 deaths

    Votes: 7 24.1%
  • 400,000 deaths or more

    Votes: 17 58.6%

  • Total voters
    29
If the Japanese didn't surrender forcing the US to invade the Home Islands, how high would US military deaths be as a result of Operation Olympic/Coronet?
 
How many POWs were there released at the end of the war? Add those, as I'm fairly certain the plan was to execute them all at or before the first landing.
 
How many POWs were there released at the end of the war?
Around 132,000. 35,000 of those were American.
Add those, as I'm fairly certain the plan was to execute them all at or before the first landing.
Here's the specific Japanese order concerning POWs:
Whether they are destroyed individually or in groups, or however it is done, with mass bombing, poisonous smoke, poisons, drowning, decapitations, or what, dispose of them as the situation dictates.

In any case it is the aim not to allow the escape of a single one, to annihilate them all, and not to leave any traces.
The executions were scheduled to occur on August 22, 1945.
 
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Based on Okinawa US units took 5% KIA among units taking that Island so thats 300,000 KIA for the mainland - Naval losses were expected to be higher given the more exposed nature of the fleets and the number of land based Kamikazi

(Didn't Truman tell Churchill that they expected 1 million US and half a million Commonwealth Casualties? He then sold Churchill on the Bomb)

Of course this assumes that the population fights, every square KM is contested and that the Russians / Commonwealth do not get involved.

The Japanese losses were expected to be horrendous - far more than those killed by the 2 bombs or who would likely have died from an extended blockade.
 
I'd expect 100,000 doing Olympic to take out Kyushu and following mop up on the mainland; Japan will be starved to collapse by the time the U.S. does other landings in 1946.
 
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Of course this assumes that the population fights, ....

This is the core question. The record for the Japanese population fighting on Saipan and Okinawa is spotty. Col Yahara the Cheif of staff for the 10th Army & senior Japanese survivor of the defenders left a account of the defenders side of the battle. Leaving aside the Okinawan militia Yahara described the Japanese civilians as ineffective, avoiding combat, surrendering, or sometimes committing suicide. Neither did he feel the Japanese reservist units called up from among the Japanese population on Okinawa were particularly effective. Finally Yahara describes a level of desertion among the Japanese soldiers not seen in the other Pacific island battles. I've checked a few other sources on this, which support either more or less Yaharas description, tho they dont always differentiate between the well trained Japanese units, the local reservists, and the Okinawan militia.

A look at other pacific battles show a wide loss ratio for US forces. Betio island is a example of the high end with depending on how its counted a 14% death rate for the attacker. At the very low end some of the assaults were at the 1-2 % level.

There is also the question of operational skill. Buckner has been criticised for sticking to a series of pedestrian frontal assaults to reduce the defense. Kruger & Eichelberger showed more imagination in their battles/campaigns and a propensity for manuver to unhinge the Japanese defense.
 
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