One name to familiarize yourself with is Edward J. Drea whose work on the IJA such as Japan's Imperial Army: Its Rise and Fall, 1853-1945 and In the Service of the Emperor: Essays on the Imperial Japanese Army provide excellent coverage of the IJA as an institution as well as its long-term shifts. Although it is anolder text, Ishiwara Kanji and Japan's confrontation with the West is a classic in the field. Likewise, Japan Prepares for Total War: The Search for Economic Security, 1919–1941 by Michael Barnhart frames the internecine squabbles between the services that spilled over into the realm of politics in terms of their definition of Japanese autarky and self-sufficiency. Some of the more recent trends in the historiography of the military and Japanese politics emphasize militarism arising out of weaknesses of its political position in the Taisho era, not its strengths. Both Leonard Humphrey's The Way of the Heavenly Sword: The Japanese Army in the 1920's and Frederick Dickenson's World War I and the Triumph of a New Japan, 1919-1930 fall within this vein.