Axis Development of the Atomic Bomb

The development of the German V-1 and V-2 rocket weapons and the jet fighter plane in the last year of the War was too late to affect events, but indicates how dangerous at all times was the German capacity to invent engines of war. Up to the last moment, German morale could be boosted by mention of der Führer's promise of secret weapons nearing readiness. America was taking notes and notice; their own secret weapons were nearing usable capability.

Albert Einstein, instigated by friendly physicists, wrote President Roosevelt in 1939 that the Nazis had the possibile capability to develope the A-Bomb and America should attend to it also. Einstein gave his concerns to better-connected colleagues to hand to Roosevelt. And FDR approved the Manhattan project and funded it with billions of dollars, all in secret. At the University of Chicago, the first nuclear chain reaction was accomplished.

At Alamogordo, New Mexico 1945, with the end of the War in Europe, the first A bomb was exploded, to the tune of attending scientists' exclamatory one-liners, and a couple of bombs were rendered ready to be dropped by B-29 bombers over the Japanese homeland.

In late April 1945, just one week after Truman reiterated what had been Roosevelt's policy of unconditional surrender, an intelligence report prepared for the Joint Chiefs of Staff warned that unconditional surrender could not be forced upon the Japanese before the middle or latter part of 1946 without a land campaign on the Japanese home islands.

Therefore, in April 1945, at the height of the Luzon and Okinawa campaigns, the Joint Chiefs of Staff instructed Admiral Nimitz and General MacArthur to make plans and preparations for an attack on Japan. Admiral King opposed any landing in Japan; he was convinced that the Japanese Army had great advantages on their home islands, and only consented to the invasion after Admiral Nimitz recommended in favor of it.

On 25 May 1945, the JCS issued a directive to begin formal planning for the campaign, code-named "Operation Downfall," which was to force Japan's unconditional surrender. Operation Downfall was divided into two major operations, Operation Olympic, the invasion of the island of Kyushu to be executed in the fall of 1945, and Operation Coronet, the invasion of Honshu, scheduled for the spring of 1946.

Meanwhile A shipment of weapons-quality uranium was discovered on a surrendered German submarine on its way to Japan: one more bit of hard evidence that, had they contrived the Bomb first, the Germans and Japanese would have exploded it upon Allied centers.

Aboard the U-234 Cargo U-boat bound for Japan when war ended was the cargo surrendered to U.S. authorities at sea carrying a total cargo of 260 tons, including uranium oxide ore, mercury, and the component parts for an Me 262 jet fighter. 234 Surrendered to destroyer escort USS Sutton east of the Flemish Cap, 14 May 1945, after two Japanese passengers committed suicide. Other passengers bound for Japan included several Luftwaffe officers and technical specialists intended to improve Japanese aircraft defenses. (The U.S. Navy used U-234 for experimental trials and then sank her off Cape Cod, November 1946)

In the western Central Pacific, the V Amphibious Corps, comprised of the Third, Fourth and Fifth Marine Divisions, assaulted Iwo Jima on 16 February 1945. The island was declared secure by the end of March and the three Marine divisions withdrew to their training bases in the Marianas and Hawaii. The third campaign identified by the JCS in its October 1944 directive began on 1 April 1945, when the Tenth Army comprised of seven divisions assaulted Okinawa. The island was not secured until three months later, on June 21. The ferocity of the Japanese defenders on Iwo Jima and Okinawa convinced American policymakers that Japan would not surrender unconditionally until she was decisively defeated at home.

On 18 June 1945, President Truman held a Japanese strategy meeting at the White House. At this meeting he was briefed by the Joint Chiefs of Staff on the elements of Operation Downfall. Truman's primary concern was on the number of casualties and whether an invasion of the home islands was necessary. General Marshall gave Truman an estimate of approximately 40,000 U.S. casualties for Operation Olympic. After hours of discussion, Truman approved further planning for Olympic, with an execution date of 1 November 1945. Operation Coronet, if needed, would be conducted in March 1946.

The initial assault would be conducted by eleven US Army infantry divisions and three Marine divisions, divided into four corps under the command of General Walter Krueger's Sixth Army: I Corps consisted of the Army's 25th, 33rd, and 41st infantry divisions; XI Corps, the Army's Americal and 43rd infantry divisions and the 1st Cavalry division; IX Corps, the reserve, the Army's 81st and 98th infantry divisions; and the V Amphibious Corps, the Second, Third, and Fifth Marine divisions. The number of ground forces to be landed in the first four days of the assault would total approximately 436,486. Follow-up forces would number 356,902. With air support personnel of 22,160, the numbers topped 800,000 for Operation Olympic. Should it be found that the fourteen divisions allotted to the Sixth Army were insufficient to capture and hold southern Kyushu, that army would be reinforced at the rate of three divisions a month from X+30 by the units earmarked for Coronet.

Thousands of land based fighters and bombers of the Far East Air Forces would provide air support for Olympic. The Far East Air Forces, under the command of General George C. Kenney, belonged to MacArthur and included the Fifth, Seventh and Thirteenth Air Forces. Also providing air support were the Fleet Air Wings based on the carriers, and the 1st, 2nd, 3rd, and 4th Marine Aircraft Wings (MAW) which were mostly land based. The MAWs would provide support in the amphibious phase under the control of Admiral Spruance's Fifth Fleet. Once established ashore on Kyushu the Marine Aircraft Wings would fall under the control of the Far East Air Forces. Also included in the operation were the strategic bombers of the Twentieth Air Force, and the 20th and 21st Bomber Commands. The thousands of B-29s from the U.S. Army Strategic Air Force in the Pacific would be conducting strategic bombing of Japanese cities.

"We must be prepared to accept heavy casualties whenever we invade Japan. Our previous success against ill-fed and poorly supplied units, cut down by our overpowering naval and air action, should not be used as the sole basis of estimating the type of resistance we will meet in the Japanese homeland where the enemy lines of communication will be short and the enemy supplies more adequate."

During the early part of 1945, as the Joint Chiefs of Staff discussed plans to force the unconditional surrender of Japan, General MacArthur's staff in Australia undertook intelligence studies to assess Japanese defensive capabilities remaining in the home islands. The second intelligence estimate to be published was much more detailed and specific in regard to the location of Operation Olympic. The USAFPAC G-2 Estimate of the Enemy Situation With Respect to an Operation Against Southern Kyushu in November 1945 was issued on 25 April 1945. On 29 July 1945, the USAFPAC G-2 issued an amendment to the 25 April intelligence estimate.

- The rate and probable continuity of Japanese reinforcements into the Kyushu area are changing the tactical and strategic situation sharply.... we are engaged in a race against time by which the ratio of attack-effort vis-a-vis defense capacity is perilously balanced.

- Unless the use of these (supply) routes is restricted by air and/or naval action ... enemy forces in southern Kyushu may be still further augmented until our planned local superiority is overcome, and the Japanese will enjoy complete freedom of action in organizing the area and in completing their preparations for defense.

This new estimate warned that if the Japanese troop deployments into Kyushu were not checked then the U.S. attack ratio may become one (1) to one (1). The figure given to Truman at the outset based on his planning called for a 3 to 1 advantage to the American invasion forces.

The suspected casualty figures were growning in mutiples of tens of thousands by the time the first A-Bomb was exploded in New Mexico. One of the impacts that this estimate had was in the mind of General Marshall, for he contemplated the possibility of using the newly developed atomic bomb against Japanese forces on Kyushu in support of the invasion instead of against Japanese cities. Japan surrendered before there were any formal revisions to the Olympic plan or new casualty estimates were made using this revised estimate of Japanese strength.

The U.S. Sixth Army provided the intelligence estimates utilized by the V Amphibious Corps for their initial planning. These estimates were basically derived from the same intelligence used by the USAFPAC estimates addressed above. But, with grave exceptions.

In a major disagreement with the USAFPAC estimate, the Sixth Army assessed that there were 5,000 enemy combat planes of all types within range of intervention. In addition, an estimated 4,000 - 5,000 training planes could be used for kamikaze attacks.

The Sixth Army also believed that the Japanese would fight the decisive battle on Kyushu, and commit all of their aircraft, primarily in kamikaze attacks. Upwards of 10,000 aircraft would be available to the Japanese to conduct an all-out suicide air offensive against the transport ships and landing craft. These attacks would be strengthened by the probable widespread use of the suicide-piloted rocket plane (BAKA), which was modeled after the German V-1 rocket bomb.

USAFPAC estimates said that Japans airforce was limited in numbers and capabilities. 2,000 would be first line aircraft, while the remainder would be training planes or obsolete models. It was expected that an intense and violent air reaction would occur prior to landing, and probably consist largely of kamikaze attacks.

The attacks would include both massed air attacks, and frequent small sorties. However, it was assessed that no more than 500 to 800 aircraft would be sacrificed in attempts to prevent the Allied landing, therefore this threat would be manageable by the massive Allied naval and air invasion force. There was the belief that the Japanese were going to save the preponderance of their aircraft for the decisive battle on the Tokyo Plain, which would come in the spring of 1946.

The kamikaze attacks against the U.S. fleet at Okinawa came after the aircraft flew more than 500 miles over open ocean. Many inexperienced pilots lost their way and never reached the American fleet. This great distance also allowed the fleet to receive early warning from picket ships and scramble fighters to engage the kamikazes. Bad weather in the target area also hampered the kamikaze pilots from acquiring their targets. With all of these difficulties, the Japanese ratio of planes launched to planes successfully striking their targets was 1 in 9.

The Japanese flew 1,840 "special-attack" planes during the battle for Okinawa. A ratio of 1 in 9 would equate to approximately 202 planes striking their targets. The U.S. Navy reported 192 ships hit by kamikaze planes during the battle of Okinawa; of these, 15 were sunk.

Although the Japanese staff planned for a hit ratio of 1 in 9, many believed that they would be far more successful. The special attack aircraft would have to fly less than 100 miles to their target with almost the entire distance spent over land masked by terrain. The U.S. fleet would have very little warning time to intercept the aircraft. Anchored troop transports, just off the coast, would be easy targets as they unloaded their cargo.

It is highly probable that the Japanese suicide attack hit ratio would have been higher, probably closer to 1 in 6 or 1 in 7. At these ratios, 1,400 to 1,600 kamikaze aircraft would have hit American ships. With their targets being transports, the casualty rate per hit would have been higher than at Okinawa where destroyers were the primary target.

In addition to the kamikaze aircraft, the U.S. fleet also would have had to deal with all of the Japanese Navy's special attack boats and midget submarines. Even if the suicide attacks were only marginally successful, the U.S. attack ratio would have eroded still farther. If the Japanese did succeed in delivering 1,500 hits against the transports, the mythical "Divine Wind" may well have blown again, turning away another invasion fleet.

On 18 July 1945, the Joint War Plans Committee issued another Memorandum for the President to assist Truman in preparing for the Potsdam Conference. This memorandum again highlights the misunderstanding of the situation on Kyushu at the strategic level. It claimed;

"the nature of the objective area in Kyushu gives maneuver room for land and sea operations. For these and other reasons it is probable that the ground cost in ground force casualties for the first 30 days of the Kyushu operation will be on the order of that for Luzon. Naval casualties will probably be at about the same rate as for Okinawa."

With the casualty ratios of those battles applied to Operation Olympic, the estimate for U.S. casualties would have been 94,000 killed and 234,000 wounded. The total casualty estimate of 328,000 equates to 57 percent of the U.S. ground forces slated for Olympic. On the Satsuma Peninsula, the V Amphibious Corps casualty estimate would have been 13,000 killed and 34,000 wounded, or approximately 54 percent of the Marine force. This casualty estimate for VAC is made without any additional Japanese forces moving into the 40th Army's zone. Add to these estimates the results of kamikaze attacks against transports, and the battle for Kyushu would have been devastating to the American people.

General MacArthur was determined to lead the largest amphibious operation in history and General Marshall was willing to support MacArthur in this endeavor. Concerned about high casualties, President Truman had little enthusiasm for a ground invasion of the Japanese home islands.

New casualty estimates based on this intelligence, would likely have influenced President Truman to use the atomic bomb as a tactical weapon against the beach defenses on Kyushu. Although probably a successful tactic to defeat the Japanese on Kyushu, historian Edward Drea points out the dreadful results of such use of the atomic bomb:

"...American GIs and Marines who would have landed on radioactive beaches - another hell, that of radiation poisoning, might well have been in store. In 1945 no one really grasped the implications of radioactive fallout, and the hellish effects would undoubtedly have persisted for decades after the explosions."

Dec 18, 1938 Otto Hahn splits the uranium atom, releasing energy. Although top officials were invited to an atomic weapons session, the agenda described the presentation as of a technical nature and lower level individuals were assigned to attend. Little interest developed. Heavy water was recognized as a requirement. The activities to destroy the only facilities in Europe at that time, in Norway, are well documented on the commando raid, Feb 28, 1943, the bombing raid, Nov 16, 1943, and the sabotage sinking of the ferry in Jan, 1944. However, Germany had pretty well given up on the bomb by mid-1943 although work continued at

Boris Pash, head of security for the Manhattan Project, and scientist Samuel Goudsmit followed the lead tanks into Paris and into Germany, looking for the German nuclear laboratory, which they found in Strasbourg. This was called Operation Alsos (Greek for "Groves"). Peter Goodchild in his book *J. Robert Oppenheimer, Shatterer of Worlds,* p. 110 said:

"Very soon a picture of the Germans' progress began to emerge. They revealed that Hitler had been told of the possibilities of a nuclear weapon in 1942 and that there had been a whole series of uranium pile experiments. But the crucial facts were that even as late as August 1944 the experiments were still at an early stage. The Germans had neither the certain information that an explosive chain reaction was possible, nor did they have the material or the mechanism to make their bomb. It was apparent that the project had moved forward hardly at all since 1942. There were one or two people in Washington who, when they read Goudsmit's final report, suspected that the information had come too easily, but most people believed it."

When the Allies found the German atomic bomb laboratory, they were amazed that it was just a small concrete reactor in a cave, too small to go critical. Yet they went to considerable trouble in a top secret program to grab these scientists because they might be useful in defeating Japan. Tom Agoston in *Blunder!* says (p. 38) that "Unknown to Allied scientists, the Germans had been able to build up a sizeable stockpile of U-235 and had held up to two tons, as well as two tons of heavy water."

William Stevenson, in *A Man Called Intrepid,* says "The Germans had the man [Heisenberg] whose theoretical work was the basis of the bomb" (p. 456) and "In the military field, the view prevailed in 1939 that the country with the greatest chance of bringing together the pieces was Germany."

The German laboratory was captured on April 21, 1945, then three months later on July 16 a bomb was tested at Alamogordo, New Mexico. Then on August 6, 1945, one was dropped on Hiroshima, and August 9 on Nagasaki. Pash and Goudsmit in Operation Alsos captured several tons of uranium and "it was shipped to Britain and then the United States, transformed into uranium hexaflouride gas for isotope separation at Oak Ridge, Tennessee, and finally in the form of U-235 used to destroy Hiroshima." (*Heisenberg's War,* p. 362.)

There is evidence to support the theory that Germany actually built the Atomic Bombs used against Japan. In Phoenix Journal #18 (*Blood And Ashes*), speaking of the Manhattan Project, "Of course, they utilized the German production urn and, actually, the bomb used on Japan was constructed in Germany" (p. 159).

It is well known that the atomic bomb was a German idea; they had the best scientists, they had a proven ability to develop advanced weapons, they had plenty of raw material. Most classified files from World War II have been routinely declassified under the provisions of the U.S. Freedom of Information Act. Tom Agoston (*Blunder!,* p. 124) said of the Alsos information, "The files continued to be suppressed and remain under lock and key in Washington, well beyond the thirty-year rule. The motive for this remains a four-decade mystery."

"The stakes in the search for the scientific expertise of Germany were high. The single most important American strike force, for example, was the Alsos raiding team, which targeted Axis atomic research, uranium stockpiles, and nuclear scientists, as well as Nazi chemical and biological warfare research. The commander of this assignment was U.S. Army Colonel Boris Pash, who had previously been security chief of the Manhattan Project - the United States' atomic bomb development program - and who later played an important role in highly secret U.S. covert action programs. Pash succeeded brilliantly in his mission, seizing top German scientists and more than 70,000 tons of Axis uranium ore and radium products. The uranium taken during these raids was eventually shipped to the United States and incorporated in U.S. atomic weapons." (Simpson, Christopher, *Blowback,* Collier Books, New York, 1988, p. 26.)

In the fall of 1940, the Japanese army concluded that constructing an atomic bomb was indeed feasible. The Institute of Physical and Chemical Research, or Rikken, was assigned the project under the direction of Yoshio Nishina. The Japanese Navy was also diligently working to create its own "superbomb" under a project was dubbed F-Go, headed by Bunsaku Arakatsu at the end of World War II.

Dr Hideki Yukawa was awarded the Nobel Price in physics in 1949 for his extensive work with the atom begun in 1941. An atomic bomb project as launched by Prime Minister Hideki Tojo in January, 1943. Former colonel Toranosuke Kawashina was in charge. Design considerations were promising. All chance of success was destroyed when a German submarine carrying two tons of uranium was captured as it approached Japan.

Although the allied atomic bomb was developed from a threat by Germany, it was not completed until after VE day. It was used to avoid the expected 500,000 to one million US casualties from the invasion of the Japanese main islands against an army of almost three million men. Kamikaze boats and planes were being stockpiled. In addition, the public was being issued weapons. Two to five million Japanese casualties were anticipated.

Japan's nuclear efforts were disrupted in April 1945 when a B-29 raid damaged Nishina's thermal diffusion separation apparatus. Some reports claim the Japanese subsequently moved their atomic operations Konan [Hungnam, now part of North Korea]. The Japanese may have used this facility for making small quantities of heavy water. The Japanese plant was captured by Soviet troops at war's end, and some reports claim that the output of the Hungnam plant was collected every other month by Soviet submarines.

There are indications that Japan had a more sizable program than is commonly understood, and that there was close cooperation among the Axis powers, including a secretive exchange of war materiel. The German submarine U-234, which surrendered to US forces in May 1945, was found to be carrying 560 kilograms of Uranium oxide destined for Japan's own atomic program. The oxide contained about 3.5 kilograms of the isotope U-235, which would have been about a fifth of the total U-235 needed to make one bomb. After Japan surrendered on 15 August 1945, the occupying US Army found five Japanese cyclotrons, which could be used to separate fissionable material from ordinary uranium. The Americans smashed the cyclotrons and dumped them into Tokyo Harbor.

"In addition to U.S. casualties, the Japanese on Kyushu would likely have suffered upwards of 2,000,000 military and civilian casualties. These projected figures for Kyushu far exceed the casualties inflicted by the atomic bombs dropped on Hiroshima and Nagasaki, which ended the War with Japan. "

"Japan was finished as a warmaking nation, in spite of its four million men still under arms. But...Japan was not going to quit. Despite the fact that she was militarily finished, Japan's leaders were going to fight right on. To not lose "face" was more important than hundreds and hundreds of thousands of lives. And the people concurred, in silence, without protest. To continue was no longer a question of Japanese military thinking, it was an aspect of Japanese culture and psychology. "

With the greater part of Japan's troop strength overseas and industrial production suffering under constant American air attacks, the defense of the Japanese home islands presented an enormous challenge to the Japanese Imperial General Headquarters (IGHQ). On 8 April 1945, the Imperial General Headquarters issued orders, to be effective 15 April, activating the First and Second General Armies.(1) These two Armies would be responsible for the ground defense of the Japanese home islands. Also, on 8 April 1945, IGHQ issued an order activating the Air General Army, effective 15 April.

The purpose of the new Air General Army was to coordinate the air defense of Japan, providing a single headquarters through which cooperation with the ground forces and the Navy could be expedited in implementing the defense of the home islands.(2) Simultaneously with the activation of the First and Second General Armies and the Air General Army, IGHQ issued orders for the implementation of Ketsu-Go (Decisive) Operation. Defensive in nature, the operation divided the Japanese home territory into seven zones from which to fight the final decisive battles of the Japanese empire.(3)

The strategy for Ketsu-Go was outlined in an 8 April 1945 Army Directive.(4) It stated that the Imperial Army would endeavor to crush the Americans while the invasion force was still at sea. They planned to deliver a decisive blow against the American naval force by initially destroying as many carriers as possible, utilizing the special attack forces of the Air Force and Navy. When the amphibious force approached within range of the homeland airbases, the entire air combat strength would be employed in continual night and day assaults against these ships. In conducting the air operations, the emphasis would be on the disruption of the American landing plans. The principal targets were to be the troop and equipment transports. Those American forces which succeeded in landing would be swiftly attacked by the Imperial Army in order to seek the decisive victory. The principal objective of the land operation was the destruction of the American landing force on the beach.

Ketsu-Go operation was designed as an all-out joint defense effort to be conducted by the entire strengths of the Army, Navy and Air Force. In the various orders and directives issued by IGHQ regarding Ketsu-Go, inter-service cooperation was stressed.(5) The basic plan for the operation called for the Navy to defend the coasts by attacking the invasion fleets with its combined surface, submarine, and air forces. The Air General Army would cooperate closely with the Navy in locating the American transports and destroying them at sea. Should the invasion force succeed in making a landing, the Area Army concerned would assume command of all naval ground forces in its area and would exercise operational control of air forces in support of ground operations. An integral part of the Ketsu-Go operational planning included reinforcement of sectors under attack by units transferred from other districts.

Since U.S. air raids had already seriously disrupted the transportation system, time schedules were planned to provide for all troop movements to be made by foot.(6) If the battle at the beach showed no prospect of a successful ending, then the battle would inevitably shift to inland warfare; hence, interior resistance would be planned. Guard units and Civilian Defense Corps personnel, with elements of field forces acting as a nucleus, would be employed as interior resistance troops. Their mission would be to attrite the Americans through guerrilla warfare, espionage, deception, disturbance of supply areas, and blockading of supplies when enemy landing forces advanced inland. It is interesting to note that the Japanese normally exercised little inter-service coordination throughout the war. Now when the homeland was threatened, the Japanese finally stressed inter-service coordination and unity of command.

Operational preparations for Ketsu-Go were conducted in three phases. The first phase, during which defensive preparations and troop unit organization was completed, continued through July 1945. The second and third phases were never completed because of the end of the war. However, the second phase, during which training was to be conducted and all defenses improved, began in August and was intended to continue through September. The third phase, which would see the completion of troop training and deployment, as well as the construction of all defense positions, would be completed during October.(7) Thus, if implemented, X-Day would have occurred just as Japanese defense plans had been completed.

For Operation Olympic, American forces would have landed against elements of the Second General Army. The defensive zone of the Second General Army was the western portion of Honshu and the islands of Shikoku and Kyushu. Within three days of being activated, on 18 April 1945, the Second General Army established its permanent headquarters in Hiroshima.(8) The Second General Army commanded the Fifteenth and Sixteenth Area Armies (equivalent to a U.S. field army). The seven defensive zones established for Ketsu-Go all had individual defensive plans. The defense of the island of Kyushu came under operation Ketsu-Go, No. 6. While Kyushu previously fell within the Western Military District, under Ketsu-Go, No. 6 the defense of Kyushu became the responsibility of the Sixteenth Area Army under the Second General Army.

The Second General Army estimated that the U.S. would enlarge its foothold on Okinawa, establish air bases on that island and, as soon as possible, begin its thrust at the Japanese archipelago via southern Kyushu. It was believed that the first objective of the Americans would be to secure operational bases for its Navy and Air Force. The Japanese correctly estimated that the American objective would be to secure Kagoshima Wan for anchorage and port facilities necessary for the buildup.(9) The earliest possible time at which an invasion attempt might be made by the U.S. was estimated to be the first part of July, when it was estimated that a strength of ten divisions could be mustered.(10) By July, Japanese officers were assessing that the invasion would occur in October or November 1945 due to the summer typhoon season.

The intent of Ketsu-Go was to inflict tremendous casualties on the American forces, thereby undermining the American people's will to continue the fight for Japan's unconditional surrender. This intent is clear in a boastful comment made by an IGHQ army staff officer in July 1945:

We will prepare 10,000 planes to meet the landing of the enemy. We will mobilize every aircraft possible, both training and "special attack" planes. We will smash one third of the enemy's war potential with this air force at sea. Another third will also be smashed at sea by our warships, human torpedoes and other special weapons. Furthermore, when the enemy actually lands, if we are ready to sacrifice a million men we will be able to inflict an equal number of casualties upon them. If the enemy loses a million men, then the public opinion in America will become inclined towards peace, and Japan will be able to gain peace with comparatively advantageous conditions.(11)

The completion of defensive preparations in Kyushu was of the greatest urgency as the initial U.S. attack was almost certain to be directed at that island. Its defense was also the most difficult of all the districts, as Kyushu had the greatest length of vulnerable sea coast to defend.(13) Since it was generally conceded that the U.S. would make initial landings in Kyushu, the Sixteenth Area Army had been given priority in the receipt of supplies and in the build-up of troop strength. Fortification construction had also been emphasized and, in general, preparations were further advanced in Kyushu than in other areas of Japan.

Ketsu-Go Operation, No. 6 was the overall guide for the defense of Kyushu, but the Sixteenth Area Army prepared its own detailed defense plan. Known as the Mutsu Operation, the Army's plan divided Kyushu into three sectors which were, in turn, broken down into seven sub-divisions.(14) The Sixteenth Area Army estimated that the main American landing effort would be directed against the southeastern coast near Miyazaki, with secondary assaults anticipated to be made at Ariake Wan and along the southwestern coast at Fugiachi Hama on the Satsuma Peninsula. (see Map 9) Mutsu Operation No. 1 was given priority over the other operations. The Japanese thus were extremely accurate as to the location of the American landing zones.

Deployed throughout Kyushu and on adjacent islands, the Sixteenth Area Army had three armies and two special forces with a total of 15 divisions, 7 independent mixed brigades, 3 independent tank brigades and 2 fortress units. For a complete listing of Japanese units, commanders, and strengths on Kyushu see Appendix D.

The defensive concept called for each army to hold one division in reserve. In the event of an invasion, the Sixteenth Area Army would concentrate a force composed principally of the armies' reserve divisions and the three tank brigades. This force would then be utilized as an assault group to be rushed to the area of the main American effort. Their mission would be to annihilate the American forces as soon after the initial landings as possible. The defensive plan called for a major counterattack to be delivered within two weeks of the initial American landings.(15) As stated by a Japanese officer, the object of the defense was "to frustrate the enemy's landing plans with a counterattack like an electric shock, and at the proper moment to annihilate the enemy by close-range fire, by throwing hand grenades, and by hand-to-hand combat."(16) Groups assigned to coastal defense were to contain the enemy, while reserve troops were being concentrated for the decisive battle or, in some cases, hold out for long periods of time until a decisive battle was won in some other area and permit the release of strength for a counterattack in the sector being held.(17)

Having no way to counter U.S. air power, every effort would be made to confuse the battle lines so as to prevent the use of naval gunfire and air power to support the ground troops. The advances of the mobile reserves would be accomplished under cover of darkness for protection from aircraft.(18)

The defense positions in Kyushu were built in accordance with the precepts laid down in The Three Basic Principles on How to Fight Americans, which had been developed as a result of lessons learned in south Pacific combat. In brief, these principles were:

The production, movement and distribution of supplies was one of the most important aspects of the defense preparations on Kyushu.(20) Preparations included the storing of munitions in caves and other underground shelters to protect them from air raids and naval bombardment.

The original Japanese plan called for the supplying of each division with one campaign unit of fire, and by July 1945 this quantity was actually in the possession of the area armies. One campaign unit of fire was sufficient ammunition for one campaign - generally understood to be a three month supply.(21) This called for the following rounds per weapon: 1,000 rounds per field piece, 25,000 rounds per machine gun, and 240 rounds per rifle.(22) However, by August 1945 with the greatly increased number of troops, it was necessary to reduce ammunition stocks to a one-half unit of fire for each unit (about 1 1/2 months). This reduction in ammunition supplies made it necessary to adjust supply plans for the high priority areas and to plan for the rapid transfer of ammunition from one area to another when the invasion was actually launched and the place and direction of attack had been determined.(23)

Air operations against American landings on Kyushu were to be the responsibility of the 5th Naval Air Fleet and 6th Air Army, both under the control of the Air General Army. They had airfields throughout Kyushu, Shikoku and Chugoku. Fields in southern Kyushu which were being attacked almost daily had been abandoned as bases and were only to be employed for staging suicide missions.

Their plan called for the neutralization of as many transports as possible as the American fleet approached the shores of Japan. If landings were made, the air forces would conduct operations to sever supply lines to facilitate the fighting of the ground forces. Planes were to be released in waves of 300-400, at the rate of one wave per hour, against the invasion fleet. Sufficient fuel had been stored for this use, but only about 8,000 pilots were available.(24) Although the pilots were poorly trained and no match against experienced American pilots, they were capable enough to carry out suicide attacks against ships.

At the end of the war, Japan had approximately 12,725 planes. The Army had 5,651 and the Navy had 7,074 aircraft of all types.(25) While many of these were not considered combat planes, almost all were converted into kamikaze planes. The Japanese were planning to train enough pilots to use all of the aircraft that were capable of flying.

Naval operations against the invasion fleet would be conducted in two phases. The first phase would consist of attriting the American fleet as it approached the home islands. The remaining 38 Japanese fleet submarines would attempt to attrite as many transports as possible. They were to serve as launch platforms for manned suicide torpedoes called "Kaitens".

Although the Kaitens had not proved too successful in operations on the open ocean, the Japanese hoped that they would be effective in the restricted waters around the home islands. The five-man midget submarines, known as "Koryu," would also be employed with either two torpedoes or an explosive charge for use in a suicide role. The Navy planned to have 540 Koryu in service by the time of the invasion. A more advanced midget submarine, the "Kairyu," was a two man craft armed with either two torpedoes or an explosive charge. Approximately 740 Kairyu were planned by the fall of 1945.

As the invasion fleet reached the landing areas, the second phase would commence. The 19 surviving Japanese destroyers would attempt to attack the American transports at the invasion beaches. Suicide attack boats, called "Shinyo," carrying 550 pounds of explosives in their bows, would strike from hiding places along the shore. The Shinyo were aiming for any craft carrying troops.

The Japanese Navy and Army had an estimated combined total of 3,300 special suicide attack boats. Finally, there would be rows of suicide frogmen called "Fukuryu" in their diving gear 30 feet or so beneath the water. The outermost row of Fukuryu would release anchored mines or carry mines to craft that passed nearby. Closer to shore, there would be three rows of divers, arrayed so that they were about 60 feet apart. Underwater lairs for the Fukuryu were to be made of reinforced concrete with steel doors. As many as 18 divers could be stationed in each underwater "foxhole".(26) Clad in a diving suit and breathing from oxygen tanks, a Fukuryu carried an explosive charge, which was mounted on a stick with a contact fuse. He was to swim up to landing craft and detonate the charge. The Navy had hoped for 4,000 men to be trained and equipped for this suicide force by October.

Ground operations against the American landings called for the ground forces to quickly determine the area of the invasion and concentrate in this area as many troops as possible before the invasion began. If the preliminary bombardment or early seizure of small islands to the south and southwest of Kyushu indicated an invasion attempt on southern Kyushu, then the 57th Division, the 4th Independent Tank Brigade, and the Chikugo and Higo Forces would move south to the vicinity of Kirishima to stage for a counterattack against the American landings.(27) The main body of infantry were to be deployed on the first commanding ground inland from the beach. These ground forces were to conduct operations so as to destroy the American forces in coastal areas before they secured firm beachheads. Should the Americans advance simultaneously in several locations, the ground forces were to direct the main operation against the main enemy force. If the enemy's main force could not be located, then the Japanese would seek a decisive battle in an area where their main force could most easily be directed. In the other operational areas, elements would carry on delaying actions in order to facilitate the operations of the main Japanese force.(28)

Medium and heavy artillery were to cover the landing craft approaches, the beaches, and plains areas surrounding the beaches. Plans for the employment of artillery seemed to combine the beach defense tactics employed on Saipan with some of the fixed defense plans employed on Iwo Jima.(29) Coastal defense and artillery batteries were to withhold their fire until landing craft came in range. However, there was no centralized control or fire-direction of the coast defense and artillery batteries.(30) The Japanese considered the massing of fires a waste of ammunition. Each artillery position was to remain in place conducting fires independently until destroyed. Artillery and mortar units were to be emplaced generally on the reverse slope of the first ridges inland from the beach and in caves further inland. The priority for employment of mortars was beach defense.

Commanders were told to be ready to swiftly divert the necessary troops and military supplies to other sectors at any time. The ground forces were to be concentrated in planned operational areas. Movement of ground forces would be primarily at night by foot, and the movement of war supplies would be by rail or water as the situation permitted. Troop movements were to be executed even under American air attacks.(31)

The Japanese had extensive experience with how the Americans conducted amphibious assaults in the Pacific. In late 1944, the Japanese also sent a team of officers to debrief the Germans on their defenses at Normandy and how the Allies assaulted to gain a foothold in Europe. From these experiences the Japanese coastal defenses on Kyushu were divided into three zones.

1. Beach Positions - These positions were to be used mainly in beach fighting and for firing against landing craft. They were to be heavily fortified and concealed for protection against naval gunfire. Coastal fortifications were constructed in cave type shelters to withstand intense bombings and bombardments, especially from naval gunfire. They were to have the ability to conduct close range actions and withstand attacks from flame-throwers, explosives, and gas. Their purpose was to defeat any landing attempt.

2. Foreground Zone - If the beach positions could not prevent a landing, then the attack was to be delayed in this zone with localized counterattacks and raids. Obstacles, hidden positions, timed land mines, and assault tunnels utilizing natural terrain features were prepared to slow the attack and to fight within the enemy lines to limit the effectiveness of naval gunfire and close air support.

3. Main Zone of Resistance - This zone was the area where the main resistance was to be established. Battalions and larger units would occupy key terrain positions which were independent of each other. (see figure 12.) These positions were to be organized mainly for antitank warfare and the fields of fire were to be short. These installations were constructed as underground fortresses capable of coping with close range actions in which flame-throwers, explosives, and gas would be used.

This resistance zone was intended to stop the American advance and set up the major counterattack that was to decisively defeat the attack.(32) The Japanese paid special attention to camouflage of their positions even during construction.(33) Defensive positions were to be concealed from air, land, and sea observation. Within all three zones, dummy positions were constructed for deception. Cave installations were to be heavily reinforced and capable of withstanding a direct hit by naval gunfire. Pillboxes, assault positions, sniper positions, and obstacles were to be organized for close quarter combat and mutually supporting. Each position was to store water, ammunition, fuel, antitank weapons, food, salt, vitamin pills, and medical supplies.(34)

Defensive measures taken inland included Rear Defense Zones. These zones were established in important areas inland as alternate positions for the area army to be used in holding out against a forceful penetration by the enemy or in support of a strategic offensive.(35) Holding positions were constructed across lines of communications to check rapid advances of enemy mechanized forces.

Inland fortifications were also constructed to provide cover and concealment for heavy equipment such as tanks, motor vehicles and artillery as well as bomb proof storage of ammunition and fuel. As on many islands throughout the Pacific, these storage shelters were impervious to American air and naval bombardment.

Mutso Operation, No. 1 covered the defense of southern Kyushu by the 40th and 57th Armies. This part of Kyushu was considered the most probable area to be invaded. Part C provided for the defense of the Satsuma Peninsula region by the 146th, 206th, and 303rd Divisions, and the 125th Independent Mixed Brigade of the 40th Army. In the event of an invasion in this area, those units would attempt to hold the V Amphibious Corps on the beaches until the mobile reserve could be assembled and moved from their inland locations. The counterattack phase would be carried out by a mobile reserve composed out of the 25th, 57th, 77th and 216th Divisions, together with the three tank brigades. The mobile reserve would advance to the vicinity of Ijuin to seal off the Satsuma Peninsula and prepare for the counterattack. There were also plans to redeploy two divisions from the Fifteenth Area Army in Honshu to augment the counterattack in southern Kyushu.(36)

The Japanese 40th Army had a strong concentration of artillery and heavy mortars on the western side of Satsuma Peninsula, south of Ijuin, in the 206th Division's zone of action. This concentration was closer to Fukiage Hama than to the beaches selected for the V Amphibious Corps.(37) Many units of the 40th Army were considered in poor state of organization and training. The 303rd and 206th Infantry divisions were particularly poor.(38)

The 77th Division, rated as A-1 by the Japanese, was under administrative control of the 40th Army and was held in reserve north of Kagoshima Wan. It was to be prepared to support the 40th Army if a landing were forced on the western shore of Satsuma Peninsula. The plan called for movement, chiefly by foot and at night, along the shore road of Kagoshima Wan, crossing the peninsula on the road system just west of Kagoshima. The estimated time for this movement was six to seven days.(39)

The 25th Division, also rated A-1 by the Japanese and under administrative control of the 57th Army, was held in reserve in the area of Miyakonojo. It was prepared to counterattack in the Miyazaki area. It likewise was to be moved chiefly on foot at night, the estimated movement time being five days.(40)

The 216th Division was centrally located in reserve at Kumamoto, prepared to move south as the situation dictated. If the preliminary bombardment or early seizure of small islands to the south and southwest of Kyushu definitely indicated an early invasion attempt on southern Kyushu, the 216th Division was to be moved, principally on foot and at night, to the area of Kirishima, northwest of Miyakonojo. This movement would have taken 7 days.(41) Likewise, if early indications pointed toward the invasion of southern Kyushu, the 57th Division and 4th Independent Tank Brigade of the 56th Army were to be withdrawn from the Fukuoka area and moved by any and all methods available to the Kirishima area.(42)

The defensive plan called for the use of the Civilian Volunteer Corps, a mobilization not of volunteers but of all boys and men 15 to 60 and all girls and women 17 to 40, except for those exempted as unfit. They were trained with hand grenades, swords, sickles, knives, fire hooks, and bamboo spears. These civilians, led by regular forces, were to make extensive use of night infiltration patrols armed with light weapons and demolitions.(43) Also, the Japanese had not prepared, and did not intend to prepare, any plan for the evacuation of civilians or for the declaration of open cities.(44) The southern third of Kyushu had a population of 2,400,000 within the 3,500 square miles included in the Prefectures of Kagoshima and Miyazaki.(45) The defensive plan was to actively defend the few selected beach areas at the beach, and then to mass reserves for an all-out counterattack if the invasion forces succeeded in winning a beachhead.(46)

The Japanese were determined to fight the final and decisive battle on Kyushu. At whatever the cost, Japanese military leaders were planning to repel any U.S. landing attempt. The defense of the Japanese home islands centered on two primary operations: the Army's fanatical defense of the beaches, and the employment of Kamikaze planes and suicide boats against transports. The Japanese plans for suicide attacks were much more extensive than anything the U.S. had yet experienced in the war. The Japanese special suicide forces were seen as a "Divine Wind" which was to save their nation just as the "Divine Wind" had driven the Mongol hordes back in the thirteenth century.(47)