2-70. The ACOS, G-9 (S-9) is the principal staff officer responsible for all matters concerning civil affairs. The G-9 (S-9) establishes the civil-military operations center, evaluates civil considerations during mission analysis, and prepares the groundwork for transitioning the area of operations from military to civilian control. The G-9 (S-9) advises the commander on the military’s effect on civilians in the area of operations, relative to the complex relationship of these people with the terrain and institutions over time. The G-9 (S-9) is responsible for enhancing the relationship between Army forces and the civil authorities and people in the area of operations. The G-9 (S-9) is required at all echelons from battalion through corps, but it is normally authorized only at division and corps. Once deployed, units below division level may be authorized an S-9. The G-9 (S-9) prepares Annex K (Civil Affairs Operations) to the operation order or operation plan. (See FM 3-57 for more information.) G-9 (S-9) responsibilities include, but are not limited to—