MIS stands up Japanese order of battle section

Courtesy Photo | Map of the Pacific theater from an Order of Battle Bulletin detailing estimated Japanese ground strengths as of 25 April 1945 (courtesy graphic).  

FORT HUACHUCA, ARIZONA, UNITED STATES

02.27.2023

Courtesy Story

U.S. Army Intelligence Center of Excellence

by Lori S. Stewart, USAICoE Command Historian

In March 1942, Col. Moses W. Pettigrew, chief of the Military Intelligence Service’s Far East Branch, formally established a Unit Identification desk to handle Japanese order of battle (OB) for the War Department. By the end of the war, the two-man desk had become the largest section in the MIS’s Military Branch and was producing Pacific order of battle intelligence for all Allied forces.

Colonel Pettigrew became the chief of the Far East Branch shortly after the Japanese attack on Pearl Harbor in December 1941. A former G-2 of the Hawaiian Department, he had nearly two years’ experience working under the previous Far East chief, Col. Rufus W. Bratton. Consumed with administrative tasks during the day, however, Pettigrew was forced to work nights analyzing the Japanese military information collected during other research activities.

In March 1942, an exhausted Pettigrew established a two-man Unit Identification desk to handle this duty. By the fall of 1942, the desk had expanded into its own branch, now under the direction of Col. (later Maj. Gen.) C. Stanton Babcock, who had been serving as military attaché in Japan at the time of the attack on Pearl Harbor. Babcock’s twelve researchers produced strategic intelligence on the Japanese ground forces throughout the Pacific theater. As information rolled in, the organization, commander, strength, equipment, combat efficiency, and location of every enemy unit were determined and cataloged. This information was passed not only to War Department planners but to commanders assigned to the theater as well.

For the first two years, veteran analysts in the branch trained any newly assigned personnel. This arrangement became untenable as expanded operations in the Pacific necessitated more trained OB specialists. On February 14, 1944, Capt. Paul Umbarger designed and supervised the branch’s first official Japanese order of battle class. The five-week class graduated twenty-six students, six of whom were selected to continue working with the branch. Five of the graduates returned to the Military Intelligence Training Center (MITC) at Camp Ritchie, Maryland, to establish a tactical OB course there. Another five transferred to the Southwest Pacific Area to establish its first OB team. The remaining graduates were assigned to the Office of Strategic Services, the Army Air Forces, and the U.S. Navy.

The branch’s responsibilities increased again in July 1944, when the U.S. Army accepted responsibility to produce Japanese order of battle intelligence for use by all Allied nations. While the British assigned some of its personnel to assist, the branch estimated it needed another 125 trained personnel by the end of the year. Maj. (later Col.) Thomas B. Roelofs, an instructor at the Command and General Staff School, was tasked to create an expanded Pacific order of battle course. The new four-week course was taught at the MITC by MIS personnel. The first class began on August 7, and the fifth and last class graduated on December 23. Of the 214 total graduates, 139 were assigned to the MIS’s OB organization to produce strategic intelligence. The course, which had been renamed the Far East Intelligence School in October, was discontinued on 1 January.

The two-man Japanese order of battle desk started in March 1942 had expanded to nearly 300 personnel by the end of the war. By that time, it had been renamed the Pacific Order of Battle Section and was the largest section within the MIS’s Military Branch. It continued producing weekly bulletins for the rest of the war. These bulletins identified, in narrative, tabular, and graphic form, new enemy units and changes in the strength and location of existing units throughout the Pacific theater. They also discussed probable future developments and offered special articles about the history of the various types of enemy units, lists of senior-level commanders, and notable changes in conditions in the Japanese homeland.

• Date Taken: 02.27.2023
• Date Posted: 02.27.2023 11:58
• Story ID: 439267
• Location: FORT HUACHUCA, ARIZONA, US