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“Operation Downfall” Japan 1945


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.        

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 8th    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, 1945. 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, 1945 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, 1945 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, 1945 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    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 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.        

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 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 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, 1945, 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 wold    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 cold 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.