An horrendous account of what might have happened had the Atomic Bombs not been dropped on Japan.

Declassified Plans for WW II Invasion of Japan

A fascinating read on what would have happened if we had not had and used the
atomic bombs on Japan to end WW II.

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

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

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

The preliminary invasion would begin 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 Americal 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

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 was 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

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

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 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
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 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 be aches 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

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

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.
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 of the many flights we had 14
Generals and Admiral s 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 half way 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".

He came up and sat in the copilotís  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 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, class of 1890
and BG Stewart, Class of 1896.

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.....