"Operations Olympic and Coronet." Topic

"…�¡The Japanese homeland was going to be bitterly contested. Both side expected the other to use poison gas. Neither had planned to use chemical weapons themselves though.
�¡The U.S. plan called for the assistance of British and Canadian troops brought in from the European theatre and a force of Australians. To ensure interoperability, MacArthur insisted that these units be trained in the U.S. in the months leading up to Coronet. Additionally, the Allied divisions would fight under a U.S.-style corps structure and the general wanted them to only use American equipment.
�¡MacArthur rejected the suggestion that a contingent of Indian troops be included in the order of battle, citing the language barrier as the main sticking point.
�¡The Manhattan Project was so secret that few involved in the planning of Downfall initially even knew of its existence. As details of the atom bombs were revealed in mid-1945, the invasion planners actually anticipated using the weapons to directly support ground combat. In fact, the Pentagon planned for up to seven nuclear bombs to be available for use in the campaign.
�¡Expecting heavy casualties, the U.S. military ordered the production of half a million Purple Heart citations in 1945. Since the war ended before the invasion, the American military put the medals into storage and has drawn from this stockpile in every war since then. There are still nearly 100,000 Purple Hearts in U.S. inventory left over from the production run prior to Downfall…"

Full article here.
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Fortunately this slaughter never happened, but it is interesting for a big wargame.

Amicalement
Armand

Very interesting about the Purple Heart stockpile

Shame British students, studying the decision to drop the bomb, are rarely taught this. It might get in the way of the accepted conclusion, that it was wrong. Similarly the effects of the two bombs on the civilian population are explicitly stressed, without the context that some cities had been devastated by fire bomb attacks as soon as the B-29's got in range.

Thanks for the link.

Not just British students

Robert Conroy's novel "1945" is a "what if" story of how the invation of Japan could have gone. The story included several instances where atomic bombs were used in support of advancing allied armies.

There was also this. Another "What if?". Robert
Staff study [US Army Forces (Pacific)]: Operation "Baker-Sixty".

"The attached Staff Study is derived from the Basic Outline Plan for "BLACKLIST" Operations, Edition Three, 8 August 1945. It constitutes the basis for directives to be issued for an initial contingent airborne operation to occupy critical portions of the Tokyo area, in case conditions exist on target date favorable for such airborne entrance."
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Basic outline plan for Blacklist operations to occupy Japan proper and Korea after surrender or collapse.

"The attached basic outline plan covers operations to occupy Japan Proper and Korea after surrender or collapse of the Japanese Government and Imperial High Command. "
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Concept of Operations : "Blacklist"

It was a basic policy in "Blacklist" to delegate authority and responsibility to designated army commanders and their corresponding naval task force commanders to the greatest extent consistent with central coordination by General Headquarters. However, the plan left nothing to chance. It could be assumed that at best there would be an attitude of non-cooperation in Japan and at worst, armed resistance in many parts of the main islands, despite such proclamations for the cessation of hostilities as would be required of the Emperor.14 Consequently, the commitment of forces was stipulated to be sufficient to reduce completely any local opposition, to establish bases at the strategic points outlined, to seize control of the higher echelons of government in both Japan and Korea, and to immobilize the armed forces of Japan. It was planned to organize these strategic centers with utmost speed in order to make them service bases from which air and ground action could be brought to bear wherever the exigencies of the situation might require.

Second priority for occupation would be restricted to strategic points to establish control of remaining major political centers and avenues of sea communications.

A third priority for occupation would be concerned with areas for the establishment of control of food supply and of principal overland and coastwise communications. "
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Tentative troop list by type units for Blacklist operations.

"The attached troop list by type unit, "BLACKLIST" Operations, contains an allocation of type units, adjusted to availability in the Western Pacific for the months of August and September 1945 for use as a guide in designation of troop units in event "BLACKLIST"' Operations become effective."
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Basic outline plan for Blacklist operations to occupy Japan proper and Korea after surrender or collapse.

"The attached basic outline plan covers operations to occupy Japan Proper and Korea after surrender or collapse of the Japanese Government and Imperial High Command."
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"DOWNFALL" THE PLAN FOR THE INVASION OF JAPAN

Evolution of "Downfall"

While the war was being fought in the Philippines and Okinawa, plans were ripening rapidly for the largest amphibious operation in the history of warfare. "Downfall," the grand plan for the invasion of Japan, contemplated a gargantuan blow against the islands of Kyushu and Honshu, using the entire available combined resources of the army, navy, and air forces.

The plans for "Downfall" were first developed early in 1945 by the Combined Chiefs of Staff at the Argonaut Conference held on the tiny island of Malta in the Mediterranean. On 9 February, just a few days before the historic Three-Power meeting at Yalta, President Roosevelt and Prime Minister Churchill were informed of the conclusions reached at Argonaut. At that time, the strategic concept of future operations in the Pacific embodied the defeat of Japan within eighteen months after Germany's surrender and included the following series of proposed objectives:

a. Following the Okinawa operation, to seize additional positions to intensify the blockade air bombardment of Japan in order to create a situation favorable to:

b. An assault on Kyushu for the purpose of further reducing Japanese capabilities by containing and destroying major enemy forces and further intensifying the blockade and air bombardment in order to establish a tactical condition favorable to:

c. The decisive invasion of the industrial heart of Japan through the Tokyo Plain.1

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"DOWNFALL" THE PLAN FOR THE INVASION OF JAPAN

Evolution of "Downfall"

While the war was being fought in the Philippines and Okinawa, plans were ripening rapidly for the largest amphibious operation in the history of warfare. "Downfall," the grand plan for the invasion of Japan, contemplated a gargantuan blow against the islands of Kyushu and Honshu, using the entire available combined resources of the army, navy, and air forces.

The plans for "Downfall" were first developed early in 1945 by the Combined Chiefs of Staff at the Argonaut Conference held on the tiny island of Malta in the Mediterranean. On 9 February, just a few days before the historic Three-Power meeting at Yalta, President Roosevelt and Prime Minister Churchill were informed of the conclusions reached at Argonaut. At that time, the strategic concept of future operations in the Pacific embodied the defeat of Japan within eighteen months after Germany's surrender and included the following series of proposed objectives:

a. Following the Okinawa operation, to seize additional positions to intensify the blockade air bombardment of Japan in order to create a situation favorable to:

b. An assault on Kyushu for the purpose of further reducing Japanese capabilities by containing and destroying major enemy forces and further intensifying the blockade and air bombardment in order to establish a tactical condition favorable to:

c. The decisive invasion of the industrial heart of Japan through the Tokyo Plain.1

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Allied Intelligence and Japanese Preparations
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Transcript of "OPERATION DOWNFALL [US invasion of Japan]: US PLANS AND JAPANESE COUNTER-MEASURES" by D. M. Giangreco, US Army Command and General Staff College, 16 February 1998
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Waiting for the invasion
[During the U.S. occupation of Japan, demobilized officers were hired to write a series of campaign histories, which were translated and mimeographed as the Japanese Monograph Series. Following are my notes from Japanese Monograph No. 23, dealing with the Imperial Army air force in the defense of the home islands. The mixture of metric and "English" measurement appears in the original. A complete set of Japanese Monographs is on microfilm at the Library of Congress. -- Dan Ford]
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Japanese plans for the defense of Kyushu.

"This report discusses the defensive plans of Kyushu, Japan, based on Sixth Army's estimates and intelligence. The information was compiled for Operation Olympic, the invasion of Japan. The report is dated 31 December 1945. "
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My step-father, Roger Adrian Cyr, drafted out of HS (Van Buren, ME) at 18, fought in Europe with the 3rd Army as a combat engineer and tanker the winter and spring of 1945. He was waiting shipment to the Pacific when the bombs were dropped.

He was never confused or sorry about their being used as he and the others with him that did not have enough "points" knew they were going to invade Japan.

Said he went back to his tent and cried for an hour when he heard about the bombings. Just complete and utter thanks that he'd get to live.

One can make the point that the Soviet invasion and declaration of war meant more to the Japanese command than did the bombings, but regardless they helped convince the Japanese to surrender.

Dan

Those that condemn the atomic bombings are wrong on all counts. The bombs did help end the war and did save hundreds of thousands of lives. They may also have saved the whole world, because if they had NOT been used during WWII does anyone really think we would have made it through the whole Cold War without someone giving in to the urge to see what one of those things could really do?

Of course I suppose I could be predjudiced. Like Dan's Step father, my own father was being trained as an infantry replacement when the war ended. His next stop would have been Japan.

Happy you enjoyed the article my friend.
Thanks for the good data Robert.

Amicalement
Armand

At the outset of the planning for Kyûshû, it was expected the Allies would outnumber the Japanese by a ratio of 3 to 1. As planning went on, intelligence reports indicated that the Japanese had move about 14 divisions to bolster the ones already there. Making the odds even. The JCS were very alarmed over this.

General Marshall made these concerns known to MacArthur but he reassured Marshall that the current plan was the best option. Marshall suggested invading northern Japan instead. But MacArthur would not budge. Marshall greatly respected MacArthur and would be very reluctant to ever overrule him.

The Japanese plan to defend Kyûshû involved a "mobile' force that would move to the most threaten sector. The problem was that due to fuel shortages they would have to march there.

They would eventually be subjected to massive air interdiction. The amount of air power available to the Allies would be unprecedented. The 8th, 20th, 21st, 14th, 9th, RAF, Commonwealth air forces, etc. Not to mention American and British Naval air.

Only the Southern half of Kyûshû would need to be occupied to leave the rest of the Japanese army to starve in in the Northern half of the island. The Southern half would be turned into a giant air field.

Some notes:

Admiral King and Hap Arnold opposed the plan to invade. They insisted that the war could be won buy blockade and bombing which in conjunction with the Soviet offensive in China, would eventually force the Japanese to capitulate. King signed off on the invasion plan but insisted he would agree to it only as a contingency plan.

Coronet would be the first time the U.S. would field an armor division in the PTO. With the possible exception of a light armor div. in the Philippines.

Marshall relayed requests from Generals Bradley, Patton and others for combat commands. MacArthur refused the request stating to the effect that continuity was important. He felt the commanders he had commanded throughout the war could do the job just fine (how many of MacArthur's Generals can you name? I bet not as many as Eisenhower's.)

As stated earlier MacArthur did not want to use any forces except US troops in the initial landings. The British would have a very large Naval presence but they were struggling to get troops to the Pacific. Britain was bankrupt by the war, so much so they continued rationing for sometime afterwards.

Marshall recommended using glider troops in the invasion but MacArthur didn't want to use them. Airborne were to be used sparingly, if I remember correctly.

IMHO: It was the combination of the two nuclear attacks AND the Soviet invasion of Manchuria, all together that resulted in the surrender. The Japanese were trying to use Stalin as a intermediary to open negotiations with the Western Allies. In the middle of this the Soviets launch a surprise invasion of Manchuria. The Soviets went through the vaunted and very depleted Kwantung Army, like a hot knife through butter.

There was the very real possibility of the Soviet's invading Northern Japan. That could not be tolerated, a communist North and a democratic South. That threat coupled with the two atomic bombs convinced the Emperor it was time to do the unthinkable. Better to be occupied by the U.S. than the Soviets.

Quite interesting points my friend.
Wonder to know if any report consider a "real" resistance from the civil population.
Like "waves of kamikaze" mobs armed with any they have.

Amicalement
Armand

Quite interesting points my friend.
Wonder to know if any report consider a "real" resistance from the civil population.

Amicalement
Armand

That would really depend on the degree of indoctrination into State Shinto of the local area, Armand.

A friend of mine tells the story of how his mom remembers the day that 73,000 Americans showed up for a 'beach party'. On Okinawa. He says she remembers her mom politely ignoring the one Japanese soldier that was demanding they give their lives to the Emperor, with bamboo spears and grenades. Obviously, Grandma disagreed, since his mom survived to marry an American soldier in the 1960s.

What would the pro-bomb lobby say to the idea, that Japan was already on the brink of surrender before the bombs were dropped?
Or that the high command was so desperate to use their new toys, that the effects of nuclear fall-out for years afterwards were barely understood, or just ignored?
Not trying to start a flame-war or anything, I saw these points raised on an American Telly show when I was in the States recently, and, as I know very little about this, wondered if it was just a 'different view for the sake of it' (see our own Napoleonic boards for further examples)

John

To some extent those of us in the West can argue that the use of the A Bombs was a measure to save lives or a means of bringing Japan to her knees or even a warning to the Soviets of the new weapon we have. Whet really matters is what did the Japanese command think. They were the ones who decided on the response of surrendering and only they true reason for so doing. What do their accounts tell us?

Edwin Hoyt, who probably covers this as well as anyone, hving had access to a lot of Japanese sources (Japan's War: The Great Pacific Conflict, 1853 to 1952. NY: McGraw (1986)); is clear on the matter. In summary, there were elements within the Japanese High Command who wanted to fight on regardless of the conswequence, even after the 2 A-bombs. It was Hirohitos direct involvement that brought about Japans surrender. Before the A-bombs to talk of surrender invited assasination by ultra-radical elements. Hoyt argues that the A-bomb didn't end the war, but that its appearance allowed the pro-peace faction a chance to be heard.

That's one authors view of course, but I haven't ever seen a credible arguement that the Japanese were going to surrender without the A-bombs put forward by anyone with authority on the subject.

FWIW my opinion is that without the A-bombs there were only three choices: continued blockade & starvation of the population, Coronet/Olympic, or a Russian invasion of the main islands. Surrender simply wasn't on the Japanese agenda without a game changer.

Tango. I've posted this before,

OLYMPIC VS KETSU-GO

Marine Corps Gazette, August 1965, Vol. 49, No. 8.

"Dr. K. Jack Bauer describes the United States' plans to assault Kyushu in the fall of 1945, a preliminary to the more massive invasion of Honshu.

Dr. Alan C. Coox authored the italicized portion of the following article, an account of the Japanese plan to defend Kyushu.

"Hell was upon us, when we lost Saipan," the Chief of the Japanese Naval General Staff told American interrogators shortly after the war. A high-ranking NGS planner explained: "After the Coral Sea and Midway, I still had hope. After Guadalcanal, I felt we could not win, only we would not lose. After the Marianas, we had little chance. After Okinawa, it was all over."

"The United Nations war objective is the unconditional surrender of the Axis Powers. The accomplishment of this objective may require the invasion of Japan." Thus stated the Joint Chiefs of Staff in a May 1943 memorandum on strategic plans for Japan. This is the earliest plant to mention the possibility of invasion. But as long as the Japanese islands remained a distant objective any discussion was academic. It was not until the 1944-1945 winter that Allied forces had reached positions which permitted a serious study of the question. "
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CHAPTER XVIII
HOMELAND DEFENSE : BASIC PLANS AND PRELIMINARY
OPERATIONS

Strategic Situation-January 1945

"As the year 1945 began, the Japanese nation faced disaster.1 The great decisive battle in the Philippines had been lost, and the enemy was moving on to invade Luzon, wresting from the Japanese their last operational base in the Philippines and extending the Allied air perimeter far out over Formosa, the China coast and southern Japan. Behind General MacArthur's forces hundreds of thousands of trained Army, Navy, and Air Force personnel were isolated, unable to contribute directly to the prosecution of the war. Ahead of the enemy, the road to the Japanese Homeland lay wide open.2

The war potential of the nation was at a record low. The backbone of both the fleet and the air forces had been broken in the Philippines, while the Army's ability to concentrate for a final effort was hampered by its commitments to many scattered and now isolated theaters. More serious than even the long chain of tactical defeats which had all but destroyed Japan's armed forces, however, was the rapid disintegration of the national war economy at its base.

Largely as a result of submarine interdiction of the South China Sea, the nation had already been deprived of essential strategic raw materials. Only in the early part of the war had Japanese shipbuilding facilities been able to keep up with sinkings by Allied submarines and planes. By January 1945, 69% of Japan's merchant fleet, including 59% of her vital oil tankers, had been sent to the bottom. Total gross cargo loadings in the quarter ending in December 1944 were a mere 33 of the wartime peak.3"
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Japanese Naval Air Forces, Ketsu-Go Operation (Suicide Aircraft)
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Operation Downfall Order Of Battle: The Allied Invasion Of Japan
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Robert

I once met a nurse who was going in with the troops for Coronet. The US Medical Corps was told to expect a million casualties. Which was more than double what we had taken so far in WWII. We can argue that the Japanese were going to surrender anyway, and the bombs were just unnecessarily prods, but that was not known. What was believed at the time was the Japanese would never surrender.

And, sad as it is, 160,000 dead from the bombs was far less than what would have happened had we invaded. I don't think the civilians would have fought much, but the Army would have used every city as a hard point, and the civilian casualties would have been dreadful.

"…Admiral King and Hap Arnold opposed the plan to invade. They insisted that the war could be won buy blockade and bombing which in conjunction with the Soviet offensive in China, would eventually force the Japanese to capitulate…"

How many time they consider a blockade of Japan implicating a starvation of the civilian population.?

Amicalement
Armand

Let me turn the question around. How could the Japanese government be so indifferent to the suffering of their own civilian population?