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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 - 61 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.
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 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.
Admiral 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.
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 same period it was learned -- via
monitoring Japanese radio broadcasts -- that Japan had closed all
schools and mobilized its school children, was arming its civilian
population and was fortifying caves and building underground
defenses.
Operation Olympic called for a four pronged assault on Kyushu. Its
purpose 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. 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 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 carriers, 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 troops.
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 America Division would land inside Ariake Bay at
beaches labeled DeSoto, Dusenberg, Essex, 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 on 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 needed. 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 Kamikaze 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. 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 suicide attacks.
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. 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.
Additionally, the 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 suicide pilot. 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. By mid-morning 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 gunners.
Carrier pilots 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 off the beaches, all
remaining Japanese aircraft would be committed to nonstop suicide
attacks, which the Japanese hoped could be sustained for 10 days.
The Japanese planned to coordinate their air strikes with attacks
from the 40 remaining submarines from the Imperial Navy -- some
armed with Long Lance torpedoes with a range of 20 miles -- when the
invasion fleet was 180 miles off Kyushu.
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 platforms. 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 he 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 theywere swollen with a fanatical fighting spirit.
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 counter attack. 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 guns.
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 charges strapped on their chests
or backs would attempt to blow up American tanks, artillery pieces
and ammunition stores as they were unloaded ashore.
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. 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 form of combat aimed at
an underground, heavily fortified, non-retreating enemy. 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 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. 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 lives.
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.
Intelligence studies 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 Nations September 2, 1945, and World War II was over.
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 Carpet.
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.
Courtesy of Duncan Trueman |
Page last revised
09/15/2016