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Olympic vs. Ketsu-Go (part 4)

continued from part 3

Japanese military circles were not unanimous as to the focus of the envisaged landings in the Kanto area. Kujukurihama and Sagami Bay would undoubtedly be assailed simultaneously, with the main American effort directed against the former-farther from Tokyo but easier to get ashore. Landings were also probable at Kashimanada. Some enemy forces might attack the peninsulas fronting on Tokyo Bay-Miura and Boso. American fighter bases would probably first have been moved up to Oshima, Omaezaki, and/or Tateyama.

Apart from problems of concentration and special-attack effectiveness, Japanese planners considered that time was working against them. Admittedly, training and construction measures could be advanced if the enemy delayed an invasion attempt till the spring of 1946, but in the meantime the air raids were bound to cause growing devastation and shortages of food and fuel. This in turn would tend to sap public morale and to affect combat operations indirectly. Evacuation of the populace from coastal battle zones posed another major problem. Many of the evacuees would be workers taken from industry, and their pull-out ought to be put off as long as possible. Transportation, housing, protection, sanitation, and food difficulties were almost insuperable for the masses of noncombatants who would have to be moved. There was even fear that the Americans might try to worsen the food problem by razing rice fields with incendiaries on a massive scale just before harvest time.

The Japanese clung to the consistent expectation that the "special attacks" by planes and ships would cripple any invasion force. Suicide operations, in fact, were viewed as the key to success in the defense of the homeland, as the Deputy Chief of the Army General Staff told an Imperial Conference in June 1945. High-spirited regular troops, supported by the fanatically patriotic citizenry in death-defying combat, would inflict fantastic losses on those invaders who managed to get ashore. The homeland was not far-off New Guinea or Guadalcanal. The odds against the defenders were far from impossible. This time, for example, shipping across immense distances would be the problem of the Americans, not the Japanese. Defending planes could operate from improvised airstrips and underground installations. The main strength of the Japanese Army remained intact. All material and psychological resources could be combined to defend hearth and home, to annihilate the invaders on soil that was known and loved. The motto would truly be, "Victory or Death!"-and the spirit would be that of the special attack corps.

A former Japanese military attaché who once served in the United States exhorted Army personnel to risk their lives and to kill several enemy soldiers with one, thus breaking the foe's will fight. "American troops," he claimed, "tend to launch bold and reckless headlong rushes when the military situation develops somewhat badly for them. That is the very best time to deal them a violent blow, by means of surprise attack."

The Chief of the Naval General Staff told the Imperial Conference in June 1945 that he believed it possible to destroy nearly half of the enemy forces before they ever landed on the Japanese beaches. This represented a significant step-up from the Admiral's very recent view that 60-70% of the enemy invaders would probably get ashore. Referring to "countermeasures," the NGS estimate of the same month asserted that although utmost efforts must be made to destroy enemy invasion forces at sea, in case landings did take place in the homeland earlier than expected (that is, in summer) only half of the troops would be able to get ashore, after the suicide assaults mounted by the combined services. In the event of a delay in the invasion timing, things would prove even more favorable for the Japanese: The possibility of annihilating the enemy forces on the high sea would be enhanced.

To evaluate the high-level assurances, map maneuvers were conducted at Fukuoka by the General Air Army and the Combined Fleet, in July 1945. The assumption was that 16 American divisions would invade southern Kyushu in October 1945-6 divisions on the Satsuma peninsula at X minus 7; ten divisions on the coast of Miyazaki at X Day. The Japanese staff officer concluded that suicide air attackers would be able to sink some 500 enemy transports, and that surface attackers would get another 125. Consequently 34% of the enemy troop strength (the equivalent of over 5 divisions) would be smashed at sea.

Depending upon various factors, many of the Japanese officers thought it not at all unreasonable to expect to be able to destroy 30-50% of the invasion forces; in fact, these calculations were judged to be conservative. Certain Army leaders, however, considered that a 15-20% destruction rate might be closer to reality. The premise of "one suicide plane (or boat), one enemy transport" struck some as unsound. Air Staff Officer Inogachi, for example, judged that in the Philippines only one of every six kamikaze planes their target; at Okinawa, approximately one in nine. In view of the inexperience of the pilots and the lack of defense against American fighters, the kamikaze planes committed to defense of the homeland might hit only 1/9 or 1/10 of their prey, even though they struck in bright moonlight or at dusk, against massed targets.

By August 1945, the Japanese armed forces had 2,350,000 officers and men under arms in the homeland, organized into 53 infantry divisions (apart from 5 divisions in Hokkaido and the Northeast Islands) and 25 brigades. Additionally there were two tank divisions and seven brigades, plus four AAA divisions. The 55 divisions were deployed as follows: Honshu-35 infantry, 2 tank; Shikoku-4 infantry, Kyushu-14 infantry. Behind the combat troops were 2,250,000 Army workers, 1,300,000 Navy workers, 250,000 Special Garrison Force personnel, and a National Volunteer Force of militia officially put at 28 million.

At 0600 on X-day Adm. Turner's TF-41 or Advance Force would cease to exist and its component parts would be absorbed into TF-40, the Amphibious Force also commanded by Kelly Turner. It would then fall to Turner's three able subordinates to get the troops established ashore. All corps would make the assault in the normal, by now nearly traditional, "two up-one back" formation used in early all landings in the Pacific. Each division in turn would follow a similar arrangement, but while the reserve regiments would be afloat off the beaches on X-day the reserve divisions would not arrive until X-2.

Adm. Wilkinson's Third Amphibious Force was charged with landing Gen. Hall's XI Corps (1st Cavalry, 43rd Infantry, and AMERICAL Divisions). After securing the Shibushi-Kashiwabaru beaches at the head of Ariake Wan the veteran troops would push in to seize Shibushi and its airfield. Then, after consolidating, the Corps would push inland towards the Aoki-Iwakawa-Takakuma-Kanoya line while making contact with I Corps to the north. After reaching this Phase II line, XI Corps would attack northward in conjunction with the other portions of Sixth Army to secure its part of the Sendai-Tsuno line.

Adm. Barbey's Seventh Attack Force drew the northern-most landings, that of Gen. Swift's I Corps (25th, 33rd, and 41st Infantry Divisions). The Corps's initial objectives were the beaches in the vicinity of Yamazaki and Matsusaki. Swift's [forces?] would follow up the seizure by pushing on to secure Matsusaki and its airfield as well as a beachhead on the south bank of the Hitosusagawa including Fukushima. I Corps was to block any Japanese southward movement along the east coast while at the same time striking inland to the Sadohara-Honjo-Takaoka-Aoidake line and southward to link up with XI Corps. Once this was accomplished Gen. Swift's troops were ready to join in the general northward advance.

The lone west coast landing would be by the battle proven Marines of Gen. Schmidt's V Amphibious Corps (2nd, 3rd, and 5th Marine Divisions). They would pour ashore from Adm. Hill's Fifth Attack Force to seize the Kaminokawa-Kushikino beaches. From there they would fan out to seize a beachhead including Sendai. Following consolidation the Marines would push on to the Kagoshima-Kawakamicho-Ichino-Sendai line while blocking any Japanese drive down the west coast. Following this the Marines would join in the general northward drive.

With the failure of the last Japanese peripheral counterattack operations, the Army and the Navy agreed (in July) upon decisive air operations in defense of the homeland-the KETSU-GO Air Operation. This time it was intended to smash the American transports and troops just before they began the landings. Convoys were to be shattered by special attack planes, day and night, at about the time the ships were anchoring at beachheads. The old Navy preference for singling out enemy aircraft carriers and task forces was diverted to the Army choice: Both the Army and Navy would combine all air strength mainly against the convoys. Ground support missions would become secondary; the emphasis was upon hit-and-run tactics. Highest priority was to be assigned Kyushu, Shikoku, and South Korea. Cooperating with these final counterattack operations in defense of the homeland would be approximately 700 Army and 5,200 Navy suicide attack boats, in addition to the 19 surviving destroyers and 38 submarines.

In mid-July the Army worked out air defense plans in conjunction with the Navy. One thousand regular planes and 1,600 suicide planes would be hurled into the defense of Kyushu, Shikoku, and/or the Kanto area. From Korea, Manchuria, and even North China, 200 regular and 500 suicide planes would be rushed in emergency. Another 500 to 1,000 suicide craft were expected to be fitted out in the homeland by August 1945. Cooperating with the Air General Army were to be 5,225 Navy planes-over 1,000 fighters, over 4,000 anti-convoy and anti-task force bombers, the rest reconnaissance aircraft. A further 600 Japanese planes from Taiwan were also slated to strike at American bases in the Ryukyus, when the Kyushu battle began. The Air General Army would direct operations covering Kyushu, from headquarters near Osaka; the Navy, from the Nara area. In all, then, against the expected invaders, there would be over 10,000 last-stand planes (75% of them special attack aircraft hastily converted from trainers). Two-thirds of the force would be committed to defend Kyushu at the outset, one-third to cover the Kanto district.

After the late shift in emphasis upon operational preparations in Kyushu, some portion of the planning to guard the Kanto region had to be sacrificed. In all probability, operational preparations in the Kanto could not be finished before the end of 1945. And if the enemy attacked the Kanto area right after Kyushu, the Japanese would find most of their remaining aerial and naval forces tied up in Kyushu. By the same token, if the enemy attacked the Kanto before Kyushu, defense of the Tokyo plain would prove to be extremely difficult.

In any event, the last test of the glorious Imperial Army forces was imminent, and they must stake all on offensive action for victory. There was even a growing feeling that Japan's entire fate must be decided in the battle on Kyushu-and Kyushu alone, where 10 million fanatical subjects buttressed the fighting troops. Fuel and food shortages were growing so severe that the Japanese nation might not be able to wage crucial struggle past the spring of 1946. In other words, Japan might not be able to fight two decisive battles.

continued in part 5