Defending the Japanese Homeland

By MSW Add a Comment 11 Min Read

Defending the Japanese Homeland

B-29s of the 500th Bomb Group on a bombing strike against Tokyo on 19 February 1945. The bombers encountered flak and were attacked by numerous Japanese fighter aircraft – “Tonys”, “Zekes” and Ki-45 “Nicks”. A Kawasaki Ki-45 “Toryu” of the 53rd Sentai piloted by 2nd Lt. Osamu Hirose rammed “Z Square 12”, a B-29 of the 881st Bomb Squadron. The bomber was cut in two and six parachutes were seen, although one was on fire and it collapsed. Of the five remaining crew members, only one survived. 2nd Lt. Hirose also perished, but his back seater, Corporal Kimio Kato was ejected from the aircraft and survived. Most people associate B-29s with the atomic bombing of two cities in Japan.

This painting shows what bomber crews had to contend with each week. Seventeen hour missions, battling flak, fighters, fatigue, weather and 200 mph jet streams at high altitude.

Japan’s ability to repel an American bombing campaign began with very few prospects in 1942 and sharply declined thereafter. Yet an enduring question is why Tokyo squandered more than two years after the Doolittle Raid, and why so little interservice coordination was attempted once B-29s appeared in homeland skies. The answer lies in the Japanese psyche more than in its military institutions.

In defending its airspace, Japan’s army and naval forces were tasked with a nearly impossible mission. Nonetheless, they failed massively in even approaching their nation’s potential to ameliorate the effects of the Allied onslaught.

Japan’s only prospect for staving off aerial immolation was to inflict unacceptable losses upon B-29s. Because of the Superfortress’s exceptional cost—some $600,000 each—a downed B-29 represented the financial equivalent of nearly three B-17s or B-24s, plus an invaluable crew. Development of ramming units demonstrates that some Japanese understood the value of a one-for-one or even two-for-one tradeoff, but the tactic largely failed for technical and organizational reasons. Therefore, defense of the home islands reverted to conventional means: flak guns and ordinary interceptors.

The resulting failure was systemic, crossing all boundaries of government and military-naval leadership. Probably the major cause was Japan’s national psychology: a collectivist culture possessing a rigid hierarchy with unusually strict protocols that inhibited breakout thinking and instilled extreme reluctance to express contrary opinions. Japan poses an intriguing puzzle for sociologists and political scientists: how an extremely well-ordered society permitted itself to make a series of disastrous decisions, each threatening its national existence. Ironically, the situation was partly explained by the atmosphere of gekokujo (“pressuring from below”) in which strident subordinates often influenced their superiors.

If interservice rivalry constituted a “second front” in Washington, D.C., it was a full contact sport in Tokyo. The postwar United States Strategic Bombing Survey concluded, “There was no efficient pooling of the resources of the Army and Navy. Responsibility between the two services was divided in a completely impractical fashion with the Navy covering all ocean areas and naval targets . . . and the Army everything else.”

In June 1944, the month of the first B-29 attack, Imperial General Headquarters combined army and navy assets in an air defense command but the navy objected to army control. A compromise was achieved with naval air groups at Atsugi, Omura, and Iwakuni assigned to the respective army district. Phone links from JAAF command centers were provided to each of the three naval units, but operational integration was seldom attempted. In fact, throughout Japan, the two air arms operated jointly in only three areas: Tsuiki on Kyushu plus Kobe and Nagoya.

A major part of the problem was astonishingly sparse allocation of fighters to air defense. As late as March 1945, Japan allotted less than one-fifth of its fighters to home defense, and the actual figure only reached 500 in July. By then very few were flying, as Tokyo hoarded its strength for the expected invasion.

In the crucial realm of radar, Japan got a jump on the world—and almost immediately lost its lead. The efficient Yagi-Uda antenna had been invented in 1926, the product of two researchers at Tohoku Imperial University. Professor Hidetsugu Yagi published the first English reference two years later, citing his nation’s work in shortwave research. But such was military secrecy and interservice rivalry that even late in the war few Japanese knew the origin of the device that appeared on downed Allied aircraft.

The Allies rated Japanese radar as “very poor,” and fighter direction remained rudimentary. While land-based radar could detect inbound formations perhaps 200 miles out, the data included neither altitude nor composition. Consequently, picket boats were kept 300 miles at sea to radio visual sightings—of marginal use in cloudy weather. However, what radar systems did exist were easily jammed by American radio countermeasures—aircraft dropping aluminum foil that clogged enemy screens.

Furthermore, the Japanese army and navy established separate warning systems, and seldom exchanged information. Even when unit-level pooling was attempted, navy officers generally refused orders from army officers.

Civilian observers were spread throughout Japan to report enemy aircraft, but predictably there was no unity. The army and navy established their own observer corps, and neither worked with the other.

Japanese navy doctrine contained an internal contradiction for air defense. A 1944 manual asserted, “In order to overcome the disadvantages imposed on fighter plane units when the enemy raids a friendly base—that is, getting fighter planes airborne on equal terms with the enemy airplanes—full use must be made of radar and other lookout methods. . . . These must be employed in the most effective manner.” But as noted, use of radar remained rudimentary.

Some pilots dismissed the state of their nation’s electronics. “Why do we need radar? Men’s eyes see perfectly well.”

Excluding mobile radar sets, at least sixty-four early-warning sites were built in the homeland and offshore islands: thirty-seven navy and twenty-seven army. But the rare assets often were squandered by duplicating effort: at four sites on Kyushu and seven on Honshu, army and navy radars were located almost side by side. The southern approaches to Kyushu and Shikoku were covered by some twenty installations but only two permanent radars are known on all of Shikoku.

Though the huge majority of Japanese radars provided early warning, some sets directed AA guns and searchlights. But apparently there was little integration of the two: some B-29 crews returned with harrowing tales of ten to fifteen minutes in a searchlight’s probing beam with minimal or no flak damage.

Apart from inadequate radar, some of Japan’s technical focus was badly misdirected. From 1940 onward, the military devoted over five years to a “death ray” intended to cause paralysis or death by very short-wave radio waves focused in a high-power beam. The nonportable unit was envisioned for antiaircraft use, but the only model tested had a range much less than firearms.

Tactically, the lack of army-navy cooperation hampered the already limited potential of Japan’s interceptors. With unit commanders conducting their own localized battles, there was little opportunity to concentrate large numbers of fighters against a bomber formation as the Luftwaffe repeatedly achieved.

Overall, Japanese fighters were spectacularly ineffective against B-29s. From more than 31,300 Superfortress sorties over the homeland, only seventy-four were known lost wholly to interceptors and perhaps twenty more in concert with flak guns. Japanese pilots logged their best performances in January and April 1945, each with thirteen bombers downed. But during fifteen months of combat, losses to interceptors amounted to merely 0.24 percent of effective B-29 sorties.

The Strategic Bombing Survey concluded, “The Japanese fighter defense system was no more than fair on paper and distinctly poor in practice. One fundamental matter stands out as the principal reason for its shortcomings—the Japanese planners failed to see the danger of allied air attacks and to give the defense system the requisite priorities.”

Lieutenant General Saburo Endo of Army Air Force Headquarters stated, “Those responsible for control at the beginning of the war did not recognize the true value of aviation . . . therefore one defeat led to another. Although they realized there was a need for merging the army and the navy, nothing was done about it. There were no leaders to unify the political and the war strategies, and the plans executed by the government were very inadequate. National resources were not concentrated to the best advantage.”

In short, in Japan’s military, parochialism trumped efficiency at every turn.

By MSW
Forschungsmitarbeiter Mitch Williamson is a technical writer with an interest in military and naval affairs. He has published articles in Cross & Cockade International and Wartime magazines. He was research associate for the Bio-history Cross in the Sky, a book about Charles ‘Moth’ Eaton’s career, in collaboration with the flier’s son, Dr Charles S. Eaton. He also assisted in picture research for John Burton’s Fortnight of Infamy. Mitch is now publishing on the WWW various specialist websites combined with custom website design work. He enjoys working and supporting his local C3 Church. “Curate and Compile“
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