Which joint operations principle addresses the coordination and unity of purpose?

The principle that addresses the coordination and unity of purpose in joint operations is the concept of "Unit of Command." This principle emphasizes the need for a single commander to lead military operations to ensure that efforts are organized, coherent, and directed towards common goals. Effective unity of command helps in minimizing confusion, establishing clear communication channels, and ensuring that all forces are working collaboratively to achieve the operational objectives.

In joint operations, where multiple branches of the military and potentially other organizations are involved, having a clear chain of command and designated leadership plays a crucial role in synchronizing actions and resources. This leads to improved efficiency and effectiveness in accomplishing missions, as all elements work towards the same strategic goals under unified guidance.

The other principles, while important for different aspects of military operations, do not focus specifically on the concept of command unity. For example, the economy of force pertains to the judicious use of resources, legitimacy involves the perception of actions taken as justified, and objective focuses on the end goals of military engagements. Each has its significance but does not directly encapsulate the idea of coordination and unity of purpose as thoroughly as the unit of command does.