If the Japanese had retreated to the main islands, would the Allies still have planned for invasion?

If the Empire of Japan had withdrawn all its military forces back to the home islands in, say, August 1944 (before the Battle of Leyte Gulf), removing its armies from China, the Philippines, and from everywhere else they were occupiers, would the US and Britain still have pursued a course of total victory including invasion?

Would they have waited for a year and then proceed to annihilate Japan from the air with more than incendiary bombing?

Or might they say it’s just not worth it? We will leave the Japanese to their own device (or own demise if they again challenge us)?

How committed would the Allies have been to accept nothing but the total subjugation of Japan and its military, and an unconditional surrender, if there was no longer anyone for them to liberate?

AIUI, pretty much from Pearl Harbor onwards, the United States was committed to nothing less than the total subjugation of Japan. No armistice or half-assed measures would do.

The Japanese used sneak attacks to invade several countries

The Japanese committed war crimes on a similar scale as the Nazis.

The Japanese government was under the control of militarists.

There is no way to believe that the Allies would give them a pass if they retreated back to within their four island home.

about 6,852 islands. :stuck_out_tongue:

Point acknowledged. :slight_smile:

Also, the Japanese people would have starved without Chinese rice and froze without SE Asian and USA oil.

Froze? They survived for many centuries without foreign oil. :dubious:
The oil was to fuel their war machine.

The policy of unconditional surrender was set in January 1943. So it was in effect in August 1944. That means the official policy of the United States* was that nothing less than a complete Japanese surrender followed by an occupation was acceptable. The justification was that the negotiated surrender in 1918 had just led to another world war.

That said, policies change. The United States might have changed its policy if the circumstances had warranted it. But I don’t see how a Japanese retreat back to their home islands would have been seen as a reason to ease off. If anything, it would have encouraged the American side to press harder.

*I realize there were many countries involved in the war. But realistically, the United States was the primary power in the war against Japan and other countries would have followed the American lead.

I guess the answer might depend on how confident the Allies were that they’d have a working and deliverable A-bomb in the near future. Because without it, they’d be facing the prospect of huge casualties for no reason other than to deliver judgment in the form of punishment.

Most countries survived without oil - in pre-industrial times. Japan needed oil both for its military and its civilian economy. And it had almost no domestic oil production.

Japan produced about three million barrels of oil each year. Its civilian economy consumed about twelve million barrels. Its military consumed about twenty-three million barrels. So even if Japan hadn’t totally disarmed it would have been dependent on foreign oil. And eighty percent of Japan’s oil imports came from the United States.

I don’t think that would be the only reason. As madsircool alluded to, Japan was still being run by a militaristic government that had invaded multiple countries and was responsible for the deaths of tens of million civilians. Leaving Japan to itself after all of that would be leaving the future open to more invasions.

Would it have been worth the many more deaths, both Japanese and Allied, to enforce the surrender? That’s harder to answer but in the end we didn’t have to; the war in the Pacific ended with much less death than was expected.

Japan didnt have the transport to repatriate its troops and civilians from its overseas empire. It was systematically raping China for food leading to massive Chinese starvation deaths. There was ample reason to defeat Japan other than delivering judgment. The same reason that we wouldnt allow the Nazis to negotiate a peace applies to the Japanese. One last reason is that a blockade of Japan would have caused even worse death and suffering for the Japanese people. The food was going to the military, Growing up we had Japanese neighbors. The father was born in the thirties and only grew to 4’8". His son was 5’9".

Huge casualties didn’t stop the Soviets from taking Berlin. Are you claiming the U.S. was less determined than the U.S.S.R? More to the point, are you claiming that the U.S. could afford to look less determined than the U.S.S.R?

Japan is a Naval power. Doing what the OP said is suicide.

The US was planning for the invasion of Japan in 1945. It didn’t matter whether or not Japan had retreated to the 4 main islands. FWIW, my father was on the planned invasion force, but Hiroshima and Nagasaki changed the equation.

Suicide for who? The Japanese or the invaders? She was a maritime nation dependent on maritime trade, yes, but by the end of the war her Navy was effectively useless against the allies, capable of little more than short-legged suicide missions of the sort that led to the loss of Yamato.

Hmm, I don’t know. If Japan had left alone all the colonies with a weakened China? I could see the Allies just shoring stuff up the way they did with Russia in Europe. Race as far inland as possible and declare that the new normal. Arm the hell out of it and be the capitalist buffer between an islands only Japan and China. Kinda like now but with a sharper border and maybe a smaller China.

And note what happened to her when her Navy was destroyed. She was unable to prevent her homeland being pounded by vast armadas of allied aircraft and to feed her people.

A Naval power has to dominate the sea approaches and naval LOCS. Simply retreating to the home islands without a fight simply gives the Americans what they want sans 200,000 casualties they took historically.

Problem with that line of thinking is that it was not an “or” questiion between invasion and nuclear attack. The Allies fully intended to do both.

This is an excellent point.

Not claiming, asking. Wondering if it might have been ‘less determined’ once Japan was no longer intent on, or capable of domination, and if there was no longer anyone for the US to liberate in the Pacific theatre.

And, by ‘ignoring’ Japan once it had retreated, the US would have more to throw at Germany (ETA: or to support Chiang Kai Shek).

Well, while they were retreating (let’s skip the part about it being pretty much impossible for them to do so), they would have been under constant attack. And a constant, accelerating attack, since presumably they would have halted all offensive operations at that point.

But, yeah…the planning for the invasion of the home islands (it’s not a single island) started, IIRC, in 1943 in earnest. This isn’t something we just pulled out of our ass at the last minute, nor something we were counting on not having to do because of the atomic bombs. We had already started staging equipment and making preparations, and I don’t see the Japanese retreating as being any sort of deterrent to us invading…just the opposite. Not sure what the dynamic you posited would have done wrt the far east…at that point, the Soviets hadn’t pivoted east and prepared to invade Manchuria and drive the Japanese out, in fact they were still totally focused on Germany. But this would have been a huge break for China and Korea…especially as a post war dynamic. But the only thing that would have stopped the US from invading would be an unconditional surrender by the Japanese, and they weren’t going to do that at this point in history. Hell, they almost didn’t do it after we dropped 2 atomic bombs and it was clear we were starting to do final staging for the invasion.

Just as a response to the last line in the OP:

I think that it was agreed that unconditional surrender was the only acceptable course for the allies, though this was solidified at the Yalta conference in early 1945. But it wasn’t about liberation, it was about ensuring that the military government would not remain in power so that we’d have to go through all of this again in 20 years or so. No way would they have just let Japan off the hook just because they withdrew from their conquered territory.

On that note, the thing is, they had some of that territory long before WWII and I seriously doubt they would or even could just pack up and go home. Korea, especially, had been in Japanese hands since the early 1900’s (I think 1905?). This stuff was considered Japanese core territory, and I don’t see them pulling up stakes and going home after that long an occupation and investment. Then there is the logistics…simply, they didn’t have the means to pull all those folks out, certainly not under fire, which they would have been.