What measures do commanders use to define lines of responsibility for friendly forces?

Commanders define lines of responsibility for friendly forces primarily through the use of Maneuver Control Measures (MCMs). MCMs help to establish clear and organized formations for units on the battlefield. They specify the boundaries and areas of operations for each unit, preventing overlap and confusion during operations. This clarity is essential for effective coordination and communication among units, ensuring that each force understands its assigned tasks and the limits of its operational area.

In contrast, while other options like Fire Support Coordination Measures (FSCMs) and Airspace Coordination Measures (ACMs) serve important functions in managing fire support and airspace respectively, they do not specifically address the delineation of responsibility among ground forces. Similarly, No-Strike Lists (NSLs) are focused on identifying targets that must be avoided, rather than defining operational boundaries for friendly units. Thus, MCMs are crucial for establishing and maintaining the structure necessary for successful military operations.