Final answer:
The U.S. Department of Defense publishes the planning order for the GFMAP.
Step-by-step explanation:
The agency that publishes a planning order outlining various milestones necessary to staff and publish the associated Global Force Management allocation plan (GFMAP) is the U.S. Department of Defense. The U.S. Department of Defense is responsible for managing and coordinating the military forces of the United States. The GFMAP is a comprehensive plan that outlines the allocation and utilization of forces for various missions and operations.