1-140. When assigning AOs, each headquarters ensures its subordinate headquarters’ capabilities align with their span of control and missions. The way in which headquarters graphically portray the operational framework and allocate resources to accomplish missions in time and space drives the pace of operations. Higher echelon headquarters create the conditions for subordinate echelons to succeed. Commanders and staffs consider the reliable availability of networks, effective span of leader control, the temporal focus at different echelons, the impact of lethality and stress on decision making, identification of targets, approval levels and timing constraints for effects delivery, sustainment requirements, physical and electro-magnetic signatures, airspace control, and clearance of fires. These considerations inform commander decisions about where capabilities are located in formations and who has ultimate responsibility for their most effective employment.