The combination of operations and intelligence seems as natural as ham and eggs.
Robert Debs Heinl, Jr.In the summer of 1917, the American Expeditionary Forces adopted the French practice of dividing the general staff of a formation, whether division, army corps, or army, into four bureaux. The first of these dealt with administration, the second with intelligence, the third with operations, and the fourth with logistics.
Soon after the end of the First World War, both the US Army and the US Marine Corps extended this system to smaller organizations, thereby providing each regiment with four ‘R’ sections and each battalion with a quartet of ‘Bn’ offices. However, where the officers in charge of ‘G’ (for ‘general staff’) shops reported to the chief of staff of the formation in which they served, their counterparts at lower levels worked directly for the executive officers of their respective units.