In C2, what is a phase line and how is it used during operations?

• A. A line on the map marking weather zones
• B. A designated line delineating phases of action to enable synchronization and control of troop movements
• C. A data processing boundary
• D. A communications channel

Answer: (B)

A phase line is a designated line on the operational map that marks distinct phases of action to synchronize and control troop movements. It provides a clear reference for when units should begin, adjust, or halt actions, ensuring that maneuver, fires, and support occur in a coordinated sequence across the force. As the operation progresses and a phase line is crossed or referenced in orders, units know their current phase and the tasks associated with it, reducing confusion and aligning actions across echelons. Phase lines help integrate movement with fires, logistics, and timing, and they guide subordinate units through planned transitions, whether actions are parallel or sequential. They are not weather boundaries, data processing boundaries, or communications channels.