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Because those who frequent this board and are not of Hawaiian, Japanese-American, or American descent/ancestry may not be aware of some of the historical record, I would ask the following:

A suggestion for those who seek to write convincingly about this topic - before you do so, ask yourself if you could answer the following questions, with citations of the relevant PUBLISHED sources (as opposed to interent discussion boards), most especially those from official USG sources and legitimately researched and published - on other words, subject to peer review, in the recognized academic sense of the term - works of history.

I would also STRONGLY suggest paying close attention to the historical realities of the question of loyalities among the AJA and JRA (points if you know what the acronyms stand for) elements of the civilian and military populations of the Territory of Hawaii in 1941-45. Some demonstration of understanding of the terms nikkei, issei, nisei, sansei, shin-issei, and kibei would be beneficial as well, as well as an understanding of international law on the status of foreign nationals and internment during wartime. Excellent and official sources on all these questions are available on-line.

Q-1. Why did the Japanese high command chose (in the fall of 1941) to go to war in the winter of 1941-42? For extra credit, list the membership of the Japanese high command, and diagram their command relationships and explain their organization for joint and combined operations.

Q-2. With the correct answer to Q-1 in mind, discuss the geostrategic positions of the Japanse vis a vis their potential enemies in the Pacific? HINT: Geography (hydrography) and geology are the important factors.

Q-3: With 1 and 2 in mind, briefly discuss the correlation of forces between the Japanese and the actual, and potential, foes in the Pacific. HINT: Don't forget where the majority of the Japanese armed forces were serving in 1941, and the origin point(s) for the logistics chain supplying those forces.

Q-4: With 1-3 in mind, discuss the logistics situation for the Japanese and their potential opponents. For extra credit, discuss the historical division and control of the historically available Japanese logistics and transportation assets between the operational needs of the armed forces and the strategic needs of the Japanese war economy.

Q-5: Briefly discuss the geography of the Pacific, wirth specific attention to distances and weather. Additional credit if you can define the shortest distance between two fixed points.

Essay Question: Write, in the standard 5-paragraph-field-order format, a military operation of your choice to be undertaken in this period. For full credit, reference every requirement of the 5-paragraph order and include an appropriate OOB.

Extra Credit Essay: Discuss the politics and loyalties of the civilian population in the Territory of Hawaii in 1941, most notably of both the Japanese-American (American citizens) and Japanese resident alien (non-citizen but long-time resident) populations; HINT: Use of official sources, including FBI and US Army reports and histories, published during or after the war, is strongly encouraged.

Regards

The Limits of Japanese Strength: December, 1941


In December of 1941, the Japanese imperial army and navy mounted a series of combined operations that stretched from Wake Island in the east to Bangkok, the Isthmus of Kra, and northeastern Malaya in the west. These operations were an impressive display of Japanese planning and operational capabilities, and the very judicious allocation of limited combat power.

However, the sheer breadth of the offensives - which were the maximum amphibious effort the Japanese military managed during the entire war - obscured some very real weaknesses in the Japanese forces, their doctrine, and leadership.

First and foremost, the Japanese operations were all against opponents that were significantly weaker, both in terms of forces in the theater and available for redeployment from elsewhere, in 1941 then at almost any other time during the conflict. The British were fully occupied in the defense of the British Isles and the Atlantic and Mediterranean; India, Australia, and New Zealand were all still essentially mobilizing, and their combat-ready forces were deployed in Africa and Middle East; the Dutch, with the Netherlands occupied, were even more limited; and the United States, which had begun mobilizing in the fall of 1940, was simultaneously equipping the large American forces being mobilized, preparing them for contingency operations in the Atlantic and ETO, and committed to supporting the European Allies - US forces in the Pacific, although significantly stronger then they had been in 1940, still came farther down the priority list then the forces at home or in the Atlantic.

Secondly, it should be understood that the Japanese rarely if ever chose to mount an opposed amphibious operation, unless the nature of the target demanded it; generally, IJA forces were landed at undefended - or, rarely, lightly defended, as at Khota Bahru - locations, and marched overland to their targets. The only significant exception to this among the December operations were the 1st and 2nd Wake assaults, and 1st Wake is notable for being among the very few WW II amphibious operations that was decisively defeated at the water's edge.

Third, a review of all of the December operations reveals just how scant Japan's resources, in both landing forces and the shipping necessary to move and sustain them, were in 1941. The demands of an industrialized island nation for shipping are always large, and the Japanese merchant marine was incapable of meeting them, even in peacetime; with the ongoing war in China, the need to maintain large and expensive ground and air forces in Manchuria and Korea to guard against the Soviets, and the occupation of French Indochina, an already thin asset had to be spread even farther, thus limiting what shipping was available for the Pacific offensives.

As it was, when the December operations were planned and then mounted, the available amphibious forces - meaning both troops and shipping - were relatively small; the total ground force allotted by the Army and Navy to the Pacific offensive amounted to four corps-level headquarters and about 12 division equivalents, something less than a quarter of the IJA's total ground forces, and a corresponding number of IJAAF air units; the IJNAF provided the bulk of the air power, including the land-based aircraft, used by the Japanese in the December offensives.

Of those 12 division equivalents, moreover, it appears that no more than about a third - perhaps four division equivalents, or about 12 brigade/regimental combat team equivalents - were ever afloat simultaneously in December, 1941.

The specifics of the Japanese offensives (see list below for sources) are as follows:

1. SHANGHAI Operation: IJA and IJN forces cooperated to occupy the International Settlement in Shanghai, China; the forces allotted amounted to small elements of the existing Japanese forces in China and IJN forces already assigned to the China Station.

2. HONG KONG Operation: The IJA's 38th Division, strongly reinforced by other elements of the Japanese forces in China, moved overland to attack the British colony; the troops were supported by a relatively small IJN task force.

3. THAILAND Operation: The IJA's 15th Army (a corps equivalent) invaded the independent but neutral kingdom overland from occupied French Indochina, with the Guards Division as the spearhead; the only amphibious element was a battalion combat team built around the 3rd Battalion of the 4th Guards Regiment, which departed Saigon 12-5-41 aboard one transport and landed at Bangkok on 12-8-41.

4. MALAYA Operation: The IJA's 25th Army (corps equivalent) invaded southern Thailand and northeastern Malaya (then a British colony) with four brigade- to division-sized forces, including a substantial force of IJAAF ground units to operate the captured airfields; these forces included:

4-A) KRA force: a brigade-sized force built around the 143rd RCT, detached from the 55th Division, which landed on eastern side of the Isthmus of Kra; it left Saigon on 12-5-41 aboard 7 transports and landed just before midnight 12-7-41;

4-B) SINGORA force: the reinforced 5th Division (built around the 11th and 41st RCTs, plus divisional- and corps-level artillery, armor, engineers, etc.), aboard 12 transports, which left Hainan 12-4-41 and also landed just before midnight 12-7;

4-C) PATTANI force: a brigade-sized force built around the 42nd RCT, detached from the 5th Division, aboard six transports, which also landed 12-7;

4-D) KHOTA BHARU force: a brigade-sized force built around the 56th RCT (detached from the 18th Division), aboard three transports, which also landed 12-7.

4-E) MALAYA SECOND WAVE: additional army elements and supply and support ships, some of them reloaded vessels of the initial convoys, left Cam Ranh Bay on 12-13 and arrived off their respective beachheads on 12-16 and 12-17;

5. BORNEO Operation: A brigade-sized force built around the IJA's 124th RCT (detached from the 56th Division) and the battalion-sized 2nd SNLF, aboard 10 transports and support vessels, left Cam Ranh Bay on 12-13. The force landed troops in Borneo on 12-16 and occupied Miri, Seria, and Lutong (5-A); six days later, elements of the same force were loaded aboard the same transports and landed at Kuching (Sarawak) on 12-23 (5-B).

6. PHILIPPINE OPERATION: The IJA 14th and 16th armies (both corps-equivalents) each provided a reinforced division and corps troops for the Philippines invasion, which proceeded in two stages against targets on Luzon and Mindanao (the two largest and the northernmost and southernmost major islands, respectively, of the archipelago): The first phase included:

6-A) LUZON STRAIT force: Small (battalion-sized or less) elements of the IJN aboard two large and several smaller transports and support vessels left Taiwan and occupied the Luzon Strait islands (Batan and Camiguin) on 12-8 and 12-10, respectively;

6-B) APARRI force: An understrength regimental-sized force (about 2,000 men drawn from the 2nd Taiwan (Formosa) RCT, part of the 48th Division) aboard seven transports, left the Pescadores (south of Taiwan) on 12-7 and landed at Aparri and Gonzaga (far northern Luzon) on 12-10.

6-C) VIGAN force: An understrength regimental-sized force (about 2,000 men also drawn from the 2nd Taiwan RCT, part of the 48th Division) aboard five transports, left the Pescadores (south of Taiwan) on 12-7 and landed at Vigan (northwestern Luzon) on 12-10.

6-D) LEGASPI force: A regimental-sized force (3,000 men drawn from the 33rd RCT, part of the 16th Division, and the 1st SNLF) aboard six transports, left Palau (Western Carolines) on 12-7 and landed at Legaspi (far southeastern Luzon) on 12-12.

6-E) DAVAO force: A brigade-sized force (5,000 men, built around the 146th RCT, part of the 56th Division) aboard 14 transports left Palau on 12-17 and landed at Davao (southern Mindanao) on 12-20; a day later, a detachment (about two battalions) was re-embarked and sailed for Jolo, in the Sulu Islands (far southwestern Philippines) landing there on 12-24.

6-F) LINGAYEN force: A large force (43,100 men) that included the bulk of the 14th Army (34,900 men), logistics personnel (4,600 men) and IJAAF personnel (3,600 men), the ground combat element included the 48th Division, built around the division's own 1st Taiwan and 48th RCTs, and the attached 9th RCT (detached from the 16th Division) plus divisional and corps-level artillery, cavalry, armor, and engineers. Loaded aboard some 60 transports, freighters, and support vessels, with about 150 purpose-built and 50 extemporized (described as "motorized sampans") landing craft embarked, the force left ports in the Pescadores and Taiwan on 12-17 and 12-18 and began landing troops at four separate points on Lingayen Gulf (Central Western Luzon) on 12-22 through 12-24;

6-G) LAMON BAY force: A reinforced brigade-sized force (7,000 men drawn from the 16th Division, including the 20th RCT and division troops) left the Ryukyus on 12-17 aboard 24 transports and began landing at Lamon Bay (Central Eastern Luzon) on 12-24.

7. GUAM Operation: A reinforced brigade-sized force, the Army's 144th RCT, (roughly 5,000 men) aboard nine transports, landed on Guam on 12-8 and rapidly overran the island.

8. WAKE Operation: An SNLF battalion, aboard four transports, left Kwajalein on 12-6 and attempted to land on Wake on 12-10; it was repulsed (First Wake); the survivors, now reinforced to a strength of 2,000 men with additional personnel and shipping (six transports total) drawn from IJN forces in the Marshalls and the Guam occupation force, landed on 12-22 and forced the island's surrender on 12-23.

9. GILBERTS Operation: Very small (company-sized or smaller) IJN elements left Jaluit 12-8 aboard small naval vessels and landed on Tarawa and Makin on 12-10.


So the grand total was approximately 14 brigade/regimental combat team equivalents, or - very roughly - four triangular infantry division equivalents and supporting elements, all only partly motorized. The Japanese infantry was, for the most part, true leg infantry, and horse-drawn artillery and logistics elements were still very much part of the IJA.

This is pretty impressive for 1941 (the Allies would not manage multi-division landings until TORCH in 1942), but it is also the largest amphibious effort the Japanese managed, historically, throughout the war. The largest subsequent amphibious operations in the NEI (the invasion of Java, for example) were no larger than corps-divisional level, and often smaller, at the brigade, regimental, or battalion scale. The reality is that Japan's greatest amphibious effort during the war amounted to the roughly simultaneous movement, landing, and support of four reinforced divisions - and this at the ranges and sea states common in the Western and Southwestern Pacific in December.

The ultimate point, of course, is that given the sheer size of the Pacific, the strength (however limited) of the Allies in their major bastions, and the relatively small forces available for the December offensives, anyone attempting to detail a alternative yet realistic strategy for the Japanese in the winter of 1941-42 has to consider the historically finite resources that were available to Japan. Otherwise, such speculation is simply fantasy.

SOURCES: I used the following books and on-line resources:

"The Rising Sun in the Pacific" by SW Morison; Vol. III of "United States Naval Operations in WW II.";

"The Fall of the Philippines" by Louis Morton, one of the US Army Official History volumes (the "Green Books");

"Chronology of the War at Sea" by Jurgen Rohwer and Gerhard Hummelchen;

Leo Niehorster's WW II Order of Battle webpage, specifically the "Initial Operations" page under the Japan heading; see
niehorster.orbat.com/014_japan/_ops.html