Army Corps of Engineers
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An Invasion Not Found in the History Books
Brig Gen R. Clements USAF ret, 16,
Deep in the recesses
of the National Archives in Washington,D.C., hidden for nearly four decades
lie thousands of pages of yellowing and dusty documents stamped "Top
Secret". These documents, now declassified, are the plans for Operation
Downfall, the invasion of Japan during World War II. Only a few Americans
in 1945 were aware of the elaborate plans that had been prepared for the
Allied Invasion of the Japanese home islands. Even fewer today are aware
of the defenses the Japanese had prepared to counter the invasion had
it been launched. Operation Downfall was finalized during the spring and
summer of 1945. It called for two massive military undertakings to be
carried out in succession and aimed at the heart of the Japanese Empire.
In the first invasion - code named Operation Olympic - American
combat troops would land on Japan by amphibious assault during the early
morning hours of November 1, 1945 - 50 years ago. Fourteen combat divisions
of soldiers and Marines would land on heavily fortified and defended Kyushu,
the southernmost of the Japanese home islands, after an unprecedented
naval and aerial bombardment.
Europe), 10th Air Force and the American Far
Eastern Air Force. More than 1.5 million combat soldiers, with 3 million
more in support or more than 40% of all servicemen still in uniform in 1945
- would be directly involved in the two amphibious assaults. Casualties
were expected to be extremely heavy.
|The second invasion on March
1, 1946 - code named Operation Coronet - would send at least
22 divisions against 1 million Japanese defenders on the main island
of Honshu and the Tokyo Plain. It's goal: the unconditional surrender
of Japan. With the exception of a part of the British Pacific Fleet,
Operation Downfall was to be a strictly American operation. It called
for using the entire Marine Corps, the entire Pacific Navy, elements
of the 7th Army Air Force, the 8 Air Force (recently redeployed from
William Leahy estimated that there would be more than 250,000 Americans
killed or wounded on Kyushu alone. General Charles Willoughby, chief
of intelligence for General Douglas MacArthur, the Supreme Commander
of the Southwest Pacific, estimated American casualties would be one
million men by the fall of 1946. Willoughby's own intelligence staff
considered this to be a conservative estimate.
During the summer of 1945, America had little time to prepare for
such an endeavor, but top military leaders were in almost unanimous
agreement that an invasion was necessary.
While naval blockade and strategic bombing of Japan was considered
to be useful, General MacArthur, for instance, did not believe a blockade
would bring about an unconditional surrender. The advocates for invasion
agreed that while a naval blockade chokes, it does not kill; and though
strategic bombing might destroy cities, it leaves whole armies intact.
So on May 25, 1945, the Joint Chiefs of Staff, after extensive deliberation,
issued to General MacArthur, Admiral Chester Nimitz, and Army Air
Force General Henry Arnold, the top secret directive to proceed with
the invasion of Kyushu. The target date was after the typhoon season.
General Douglas MacArthur estimated American
casualties would be one million men by the fall of 1946
was to seize and control the southern one-third
of that island and establish naval and air bases, to tighten the naval blockade
of the home islands, to destroy units of the main Japanese army and to support
the later invasion of the Tokyo Plain.
Meeting at Potsdam
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President Truman approved
the plans for the invasions July 24. Two days later, the United
Nations issued the Potsdam Proclamation, which called upon Japan
to surrender unconditionally or face total destruction. Three days
later, the Japanese governmental news agency broadcast to the world
that Japan would ignore the proclamation and would refuse to surrender.
During this sane period it was learned -- via monitoring Japanese
radio broadcasts -- that Japan had closed all schools and mobilized
its schoolchildren, was arming its civilian population and was fortifying
caves and building underground defenses.
Operation Olympic called for a four pronged assault on Kyushu. Its
The preliminary invasion
would began October 27 when the 40th Infantry Division would land on a
series of small islands west and southwest of Kyushu. At the same time,
the 158th Regimental Combat Team would invade and
hundreds of Navy fighters, dive bombers and
. torpedo planes would hit targets all over the island of Honshu. The 3,000
ship Fifth Fleet, under Admiral Raymond Spruance, would carry the invasion
| occupy a small island 28 miles
south of Kyushu. On these islands, seaplane bases would be established
and radar would be set up to provide advance air warning for the invasion
fleet, to serve as fighter direction centers for the carrier-based
aircraft and to provide an emergency anchorage for the invasion fleet,
should things not go well on the day of the invasion. As the invasion
grew imminent, the massive firepower of the Navy - the Third and Fifth
Fleets -- would approach Japan. The Third Fleet, under Admiral William
"Bull" Halsey, with its big guns and naval aircraft, would
provide strategic support for the operation against Honshu and Hokkaido.
Halsey's fleet would be composed of battleships, heavy cruisers, destroyers,
dozens of support ships and three fast carrier task groups. From these
Admiral William "Bull" Halsey
Hellcat folding wings on carrier (Nat'l Archives)
|Several days before the invasion,
the battleships, heavy cruisers and destroyers would pour thousands
of tons of high explosives into the target areas. They would not cease
the bombardment until after the land forces had been launched. During
the early morning hours of November 1, the invasion would begin. Thousands
of soldiers and Marines would pour ashore on beaches all along the
eastern, southeastern, southern and western coasts of Kyushu. Waves
of Helldivers, Dauntless dive bombers, Avengers, Corsairs, and Hellcats
from 66 aircraft carriers would bomb, rocket and strafe enemy defenses,
gun emplacements and troop concentrations along the beaches.
The Eastern Assault Force
consisting of the 25th, 33rd and 41st Infantry Divisions would land near
Miyaski, at beaches called Austin, Buick, Cadillac, Chevrolet, Chrysler,
and Ford, and move inland to attempt to capture the city and its nearby
airfield. The Southern Assault Force, consisting of the 1st Cavalry Division,
the 43rd Division and Americal Division would land inside Ariake Bay at
beaches labeled DeSoto, Dusenberg, Ease, Ford, and Franklin and attempt
to capture Shibushi and the city of Kanoya and its airfield.
On the western shore
of Kyushu, at beaches Pontiac, Reo, Rolls Royce, Saxon, Star, Studebaker,
Stutz, Winston and Zephyr, The V Amphibious Corps would land the 2nd,
3rd and 5th Marine Divisions, sending half of its force inland to Sendai
and the other half to the port city of Kagoshima.
On November 4, the Reserve
Force, consisting of the 81st and 98th Infantry Divisions and the 11th
Airborne Division, after feigning an attack of the island of Shikoku,
would be landed -- if not needed elsewhere -- near Kaimondake, near the
southernmost tip of Kagoshima Bay, at the beaches designated Locomobile,
Lincoln, LaSalle, Hupmobile, Moon, Mercedes, Maxwell, Overland, Oldsmobile,
Packard and Plymouth.
Olympic was not
just a plan for invasion, but for conquest and occupation as well. It
was expected to take four months to achieve its objective, with the three
fresh American divisions per month to be landed in support of that operation
If all went well with
Olympic, Coronet would be launched March 1, 1946. Coronet
would be twice the size of Olympic, with as many as 28 divisions
landing on Honshu.
All along the coast east
of Tokyo, the American 1st Army would land the 5th, 7th, 27th, 44th, 86th,
and 96th Infantry Divisions along with the 4th and 6th Marine Divisions.
At Sagami Bay, just south
of Tokyo, the entire 8th and 10th Armies would strike north and east to
clear the long western shore of Tokyo Bay and attempt to go as far as
Yokohama. The assault troops landing south of Tokyo would be the 4th,
6th, 8th, 24th, 31st, 37th, 38th and 8th Infantry Divisions, along with
the 13th and 20th Armored Divisions.
|Following the initial assault,
eight more divisions - the 2nd, 28th, 35th, 91st, 95th, 97th and 104th
Infantry Divisions and the 11th Airborne Division -- would be landed.
If additional troops were needed, as expected, other divisions redeployed
from Europe and undergoing training in the United States would be
shipped to Japan in what was hoped to be the final push.
Captured Japanese documents
and post war interrogations of Japanese military leaders disclose that
information concerning the number of Japanese planes available for the
defense of the home islands was dangerously in error.
During the sea battle
at Okinawa alone, Japanese kamakaze aircraft sank 32 Allied ships and
damaged more than 400 others. But during the summer of 1945, American
top brass concluded that the Japanese had spent their air force since
American bombers and fighters daily flew unmolested over Japan.
What the military leaders
did not know was that by the end of July the Japanese had been saving
all aircraft, fuel, and pilots in reserve, and had been feverishly building
new planes for the decisive battle for their homeland.
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As part of Ketsu-Go, the name for the plan
to defend Japan -- the Japanese were building 20 suicide takeoff
strips in southern Kyushu with underground hangars. They also had
35 camouflaged airfields and nine seaplane bases.
On the night before the expected invasion, 50 Japanese seaplane
bombers, 100 former carrier aircraft and 50 land based army planes
were to be launched in a suicide attack on the fleet.
The Japanese had 58 more airfields in Korea,
western Honshu and Shikoku, which also were to be used for massive
Allied intelligence had established that
the Japanese had no more than 2,500 aircraft of which they guessed
300 would be deployed in suicide attacks.
hoped could be sustained for 10 days. The Navy
-- some armed with Long Lance torpedoes with a range of 20 miles -- when
the invasion fleet was 180 miles off Kyushu
In August 1945, however, unknown to Allied intelligence, the Japanese
still had 5, 651 army and 7,074 navy aircraft, for a total of 12,
725 planes of all types. Every village had some type of aircraft
manufacturing activity. Hidden in mines, railway tunnels, under
viaducts and in basements of department stores, work was being done
to construct new planes.
Japanese were building newer and more effective models of the Okka,
a rocket-propelled bomb much like the German V-1, but flown by a
When the invasion
became imminent, Ketsu-Go called for a fourfold aerial plan of attack
to destroy up to 800 Allied ships.
While Allied ships were approaching Japan,
but still in the open seas, an initial force of 2,000 army and navy
fighters were to fight to the death to control the skies over Kyushu.
A second force of 330 navy combat pilots were to attack the main
body of the task force to keep it from using its fire support and
air cover to protect the troop carrying transports. While these
two forces were engaged, a third force of 825 suicide planes was
to hit the American transports.
As the invasion convoys approached their
anchorages, another 2,000 suicide planes were to be launched in
waves of 200 to 300, to be used in hour by hour attacks.
of the first day of the invasion, most of the American land-based
aircraft would be forced to return to their bases, leaving the defense
against the suicide planes to the carrier pilots and the shipboard
crippled by fatigue would have to land time and time again to rearm
and refuel. Guns would malfunction from the heat of continuous firing
and ammunition would become scarce. Gun crews would be exhausted
by nightfall, but still the waves of kamikaze would continue. With
the fleet hovering Japanese planned to coordinate their air strikes
with attacks from the 40 remaining submarines from the Imperial
off the beaches, all remaining Japanese aircraft would be committed
to nonstop suicide attacks, which the Japanese
The Imperial Navy had
23 destroyers and two cruisers which were operational. These ships were
to be used to counterattack the American invasion. A number of the destroyers
were to be beached at the last minute to be used as anti-invasion gun
Once offshore, the invasion
fleet would be forced to defend not only against the attacks from the
air, but would also be confronted with suicide attacks from sea. Japan
had established a suicide naval attack unit of midget submarines, human
torpedoes and exploding motorboats
The goal of the
Japanese was to shatter the invasion before the landing. The Japanese
were convinced the Americans would back off or become so demoralized
that they would then accept a less-than-unconditional surrender
and a more honorable and face-saving end for the Japanese.
But as horrible
as the battle of Japan would be off the beaches, it would be on
Japanese soil that the American forces would face the most rugged
and fanatical defense encountered during the war.
Throughout the island-hopping
Pacific campaign, Allied troops had always out numbered the Japanese by
2 to 1 and sometimes 3 to 1. In Japan it would be different. By virtue
of a combination of cunning, guesswork, and brilliant military reasoning,
a number of Japan's top military leaders were able to deduce, not only
when, but where, the United States would land its first invasion forces.
Facing the 14 American
divisions landing at Kyushu would be 14 Japanese divisions, 7 independent
mixed brigades, 3 tank brigades and thousands of naval troops. On Kyushu
the odds would be 3 to 2 in favor of the Japanese, with 790,000 enemy
defenders against 550,000 Americans. This time the bulk of the Japanese
defenders would not be the poorly trained and ill-equipped labor battalions
that the Americans had faced in the earlier campaigns.
|The Japanese defenders would
be the hard core of the home army. These troops were well-fed and
well equipped. They were familiar with the terrain, had stockpiles
of arms and ammunition, and had developed an effective system of transportation
and supply almost invisible from the air. Many of these Japanese troops
were the elite of the army, and they were swollen with a fanatical
Japan's network of beach
defenses consisted of offshore mines, thousands of suicide scuba divers
attacking landing craft, and mines planted on the beaches. Coming ashore,
the American Eastern amphibious assault forces at Miyazaki would face
three Japanese divisions, and two others poised for counterattack. Awaiting
the Southeastern attack force at Ariake Bay was an entire division and
at least one mixed infantry brigade.
On the western shores
of Kyushu, the Marines would face the most brutal opposition. Along the
invasion beaches would be the three Japanese divisions , a tank brigade,
a mixed infantry brigade and an artillery command. Components of two divisions
would also be poised to launch counterattacks.
If not needed to reinforce
the primary landing beaches, the American Reserve Force would be landed
at the base of Kagoshima Bay November 4, where they would be confronted
by two mixed infantry brigades, parts of two infantry divisions and thousands
of naval troops.
All along the invasion
beaches, American troops would face coastal batteries, anti-landing obstacles
and a network of heavily fortified pillboxes, bunkers, and underground
fortresses. As Americans waded ashore, they would face intense artillery
and mortar fire as they worked their way through concrete rubble and barbed-wire
entanglements arranged to funnel them into the muzzles of these Japanese
charges strapped on their chests or backs would
attempt to blow up American tanks, artillery pieces and ammunition stores
as they were unloaded ashore.
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(Image courtesy Wikopedia)
|On the beaches and beyond would
be hundreds of Japanese machine gun positions, beach mines, booby
traps, trip-wire mines and sniper units. Suicide units concealed in
"spider holes" would engage the troops as they passed nearby.
In the heat of battle, Japanese infiltration units would be sent to
reap havoc in the American lines by cutting phone and communication
lines. Some of the Japanese troops would be in American uniform, English-speaking
Japanese officers were assigned to break in on American radio traffic
to call off artillery fire, to order retreats and to further confuse
troops. Other infiltration with demolition
Beyond the beaches were
large artillery pieces situated to bring down a curtain of fire on the
beach. Some of these large guns were mounted on railroad tracks running
in and out of caves protected by concrete and steel.
combat aimed at an underground, heavily fortified,
|The battle for Japan would be
won by what Simon Bolivar Buckner, a lieutenant general in the Confederate
army during the Civil War, had called "Prairie Dog Warfare."
This type of fighting was almost unknown to the ground troops in Europe
and the Mediterranean. It was peculiar only to the soldiers and Marines
who fought the Japanese on islands all over the Pacific -- at Tarawa,
Saipan, Iwo Jima and Okinawa. Prairie Dog Warfare was a battle for
yards, feet and sometimes inches. It was brutal, deadly and dangerous
had become a part of the National Volunteer
Combat Force. They were armed with ancient rifles, lunge mines, satchel
charges, Molotov cocktails and one-shot black powder mortars. Others were
armed with swords, long bows, axes and bamboo spears. The civilian units
were to be used in nighttime attacks, hit and run maneuvers, delaying actions
and massive suicide charges at the weaker American positions.
cave found on Guam
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In the mountains behind the Japanese beaches
were underground networks of caves, bunkers, command posts and hospitals
connected by miles of tunnels with dozens of entrances and exits.
Some of these complexes could hold up to 1,000 troops.
In addition to the use of poison gas and
bacteriological warfare (which the Japanese had experimented with),
Japan mobilized its citizenry.
Had Olympic come about, the Japanese
civilian population, inflamed by a national slogan - "One Hundred
Million Will Die for the Emperor and Nation" - were prepared
to fight to the death. Twenty Eight Million Japanese
cave found on Iwo Jima
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cave found on Iwo Jima
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At the early stage of the invasion, 1,000
Japanese and American soldiers would be dying every hour
The invasion of Japan never became a reality
because on August 6, 1945, an atomic bomb was exploded over Hiroshima.
Three days later, a second bomb was dropped on Nagasaki. Within
days the war with Japan was at a close.
Had these bombs not been
dropped and had the invasion been launched as scheduled, combat casualties
in Japan would have been at a minimum of the tens of thousands. Every
foot of Japanese soil would have been paid for by Japanese and American
One can only guess at
how many civilians would have committed suicide in their homes or in futile
mass military attacks.
In retrospect, the 1
million American men who were to be the casualties of the invasion, were
instead lucky enough to survive the war.
and military estimates made 50 years ago, and not latter-day speculation,
clearly indicate that the battle for Japan might well have resulted in
the biggest blood-bath in the history of modern warfare.
Far worse would be what
might have happened to Japan as a nation and as a culture. When the invasion
came, it would have come after several months of fire bombing all of the
remaining Japanese cities. The
cost in human life that resulted from the two atomic blasts would be small
in comparison to the total number of Japanese lives that would have been
lost by this aerial devastation.
||With American forces locked in
combat in the south of Japan, little could have prevented the Soviet
Union from marching into the northern half of the Japanese home islands.
Japan today could be divided much like Korea and Germany.
The world was spared
the cost of Operation Downfall, however, because Japan formally
surrendered to the United States September 2, 1945, and World War II was
The aircraft carriers,
cruisers and transport ships scheduled to carry the invasion troops to
Japan, ferried home American troops in a gigantic operation called Magic
In the fall of 1945,
in the aftermath of the war, few people concerned themselves with the
invasion plans. Following the surrender, the classified documents, maps,
diagrams and appendices for Operation Downfall were packed away
in boxes and eventually stored at the National Archives. These plans that
called for the invasion of Japan paint a vivid description of what might
have been one of the most horrible campaigns in the history of man. The
fact that the story of the invasion of Japan is locked up in the National
Archives and is not told in our history books is something for which all
Americans can be thankful.
I had the distinct privilege of being assigned
as later commander of the 8090th PACUSA detach, 20th AAF, and one of the
personal pilots of then Brig General Fred Irving USMA 17 when he was commanding
general of Western Pacific Base Command. We had a brand new C-46F tail
number 8546. It was different from the rest of the C-46 line in that it
was equipped with Hamilton Hydromatic props whereas the others had Curtis
electrics. On one ofthe many flights we had 14 Generals and Admirals aboard
on an inspection trip to Saipan and Tinian. Notable aboard was General
Thomas C. Handy, who had signed the operational order to drop the atomic
bombs on Japan. President Truman's orders were verbal . He never signed
an order to drop the bombs. On this particular flight, about halfway from
Guam to Tinian, a full Colonel (General Handy's aide) came up forward
and told me that General Handy would like to come up and look around.
I told him, Hell yes, he can fly the airplane if he wants to, sir
about General Irving. He was one of the finest
gentleman I ever met. He was the oldest living graduate of West Point when
he passed on at 100+. He was one of three Generals who had the honor of
being both the Supe and Com of West Point. I think the other gentleman were
BG Sladen clliSS of 1890 and BG Stewart Class of 1896
|He came up and sat in the copilot's
seat, put on the headset and we started chatting. I asked him if he
ever regretted dropping the bombs. His answer was, Certainly not.
We saved a million lives on both sides by doing it. It was the right
thing to do I never forgot that trip and the honor of being able to
talk to General Handy. I was a Lt at the time. A postscript
"I asked him if he ever regretted dropping
the bombs. His answer was, Certainly not. We saved a million lives
on both sides by doing it."
I am very happy the invasion never came off because if it had I don't think
I would be writing this today. We were to provide air support for the boots
on the ground guys. The small arms fire would have been devastating and
lethal as hell to fly through .. Just think what it would have been like
on the ground .....
But, C'est !a vive. You do what needs to be done. You don't act like gutless
wonders and carry peace signs around ....
"Of course we celebrated (the bombing
if Hiroshima.) We were fully aware that our death sentence had been lifted."
Major General Will Simlik, USMC
Suggested by Tom Kercher and John Hopkins
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