The Japanese ground forces in WW2 are an enigma - a seemingly terribly backwards army, lacking heavily for modern equipment, which managed an incredible spurt of military genius that conquered much of China and almost all of Southeast Asia, before collapsing under the inexorable massive material, industrial, and operational superiority of the United States. Understanding the deeper details of the Japanese army (as well as the navy's ground forces, since in the terrible rivalry between the IJN and the IJA, both sides had both naval and land forces) can be somewhat difficult, but thankfully there are now some strong books dedicated to the subject, and a key one among them is Leland Ness' book Rikugan: Guide to Japanese Ground Forces, 1937-1945: Volume 1: Tactical Organization of Imperial Japanese Army and Navy Ground Forces. This lengthy sourcebook, the first of a two volume set, is devoted to the organizational structure of Japan's ground forces, and makes for an impressively detailed, if somewhat dry certainly, sourcebook which is sure to be very useful for those people who want a thorough amount of detail on the subject.
Rikugan is, without a doubt I am quite certain, the most complete and well sourced book in existence on the organization, evolution, and structure, of the ground forces of the Imperial Japanese Army and Navy both before, and during the Second World War. The product of evidently decades of research, the sheer degree of effort which went into it is stunning. Tracked the organization of the Japanese military down to the level of even small oceanic garrisons and anti-aircraft units is incredible, especially in view of the fragmented and poorly preserved Japanese wartime records, from a state which burned or destroyed so many of its papers at the same time as its empire faced the funeral pyre. This amazing level of detail makes it into a great sourcebook for even the most specialized subjects of Japanese military organization.
Such an elaborate and complete analysis is very useful for understanding the structure of Japanese units, such as the organization of infantry divisions and infantry units down to even the squad levle. Their reorganization, types, expansion, equipment, manning - all are excellently examined. Oceanic divisions are a good example of this. These were units that were paired down almost entirely for fighting in the Pacific islands, lacking completely in integral transport, reliant on boats, shipping, and static fighting. The book's spotlight on units like this, and its understandable and well-structured explanation for their purpose, helps one understand the limitations of the Japanese military and how it sought to adapt to incredibly difficult conditions.
It also does a decent job of putting this into international context and explaining limitations of Japanese units, the most consistent one it seems being inadequate transport. This could have been improved, I feel, by further elaboration on the theme, discussing the direct limitations of Japanese units in terms of mobility and range by their principally horse-based means of transportation, and some comparison to other armies, such as the Soviets, Germans, or perhaps most relevantly, the Italians, who too had their issues with full motorization and logistics. But as a whole it is reasonably decent at noting the comparison between Japanese units and international counterparts, particularly for firepower - another great drawback of Japanese units, although not quite as bad as their logistics it seems/
Other improvements could have been made for divisional schemas. There is an excellent manpower list, which shows the formations' TOWs, but a schema such as a real divisional map would have been great from time to time to help things be taken in at a glance. There are some photos throughout the book, but these are not numerous.
Cavalry is treated in a similar light, showing the organization of cavalry brigades, their manpower, and supporting arms, in a very brief chapter which shows the small size of Japanese cavalry.
Armor is longer but similar in theme, laying out the organization of Japanese tank units and their tank types, particularly the abortive attempt at forming a mechanized army in Manchuria with two armored divisions (which lacked too heavily for supporting arms and particularly logistics), the influence of German armored successes on the Japanese which occasioned the previous experimentation, and various smaller units.
After this comes the turn of the non-divisional artillery, such as siege artillery, a small number of independent field artillery units, mountain artillery, etc. As with other chapters, there is extensive amounts of information supplied not just about the guns, but also about their supporting infrastructure, equipment, and general battery and unit organization. Some small amount of rocket and self-propelled artillery was tried at the end of the war, with the rocket artillery functioning more like mortars than European-style mass-salvo rocket units.
The chapter on anti-aircraft units relates a stunning number of different anti-aircraft organizations, covering a huge variety of different roles, emplacements, and gun types, from home-defense regiments to colonial AA formations, as well as field AA.
Various miscellaneous army units appear in the seventh chapter, such as the airborne formations, commandos, airfield defense troops, while the eighth covers the Japanese equivalent of marines, the SNLF, who were actually quite the opposite of the American model - basically just landing parties who were to land an seize a key point, assembled for singular operations, then disbanded afterwards. There were also defense units drawn up in Japan as the end of the war and possible US invasion drew closer. and various IJN garrison troops.
Organizationally, the first part of the book discusses the general history of the Japanese ground forces, such as the army's Interwar military organization and expansion, the pressures which drove it into Manchuria, then China, and onwards in WW2, its infantry divisions, various army TOEs, and the ultimate course of the army during the war.
After this, it switches to exploring the infantry, how it was structured after WW1 down to the squad level, some of the basic weapons it had and later on also including support arms such as artillery in infantry divisions, division organizations and manpower including the new wartime divisions, as well as specific theater requirements such as Manchuria, Burma, or Southeast Asia. In addition, it generally discusses the strengths and limitations of these divisional and infantry organizations as it relates them. Oceanic and security divisions would also come to be established, sacrificing mobility for limiting tonnage requirements or as static garrison troops. There are a very large number of different organizational types and formations related ranging from independent detachments to mortar units to anti-tank guns to reserve formations.
The subject of the Japanese army in WW2 is one where the finer details are often difficult to ferret out. A book like Rikugun helps to fulfill this gap. There aren't too many readers who need its great complexity and certainly excessive (for the neophyte) detail, but for anyone interested in such a complete, thorough, and exhaustive understanding of the ground force's structure, it meets the needs brilliantly.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2021 Ryan C Thomas