Which principle ensures a single commander has authority over all forces assigned to a task?

• A. Unity of command.
• B. Group identity.
• C. Integrated staff for the units.
• D. Reasonable span of control.

Answer: (A)

Unity of command means there is one commander with authority over all forces assigned to a task, which allows for clear, unified direction and a single set of priorities. When one person directs everything, plans, sequencing, and resource allocation come from a single intent, preventing conflicting actions and confusion on the battlefield. This clarity makes accountability straightforward—the commander is responsible for achieving the mission with all assigned elements working toward the same objective. In Marine operations, that single-line authority keeps infantry, aviation, and support components synchronized under one plan, enabling rapid decisions and cohesive execution.

Group identity focuses on cohesion and morale rather than formal authority to direct others, so it doesn’t solve who commands the task. An integrated staff helps with coordination and advisory support, but it does not by itself grant overarching authority over all forces. Reasonable span of control deals with how many subordinates a commander can effectively manage, affecting structure and supervision, not who ultimately directs all forces for a given task.