Which of the following is NOT one of the 9 principles of Joint Operations?

In the context of joint military operations, the principles serve as foundational guidelines that inform decision-making and operational planning. While "Economy of Force," "Objective," and "Simplicity" are indeed recognized principles, "Legitimacy" is not one of the established 9 principles of Joint Operations. The 9 principles primarily focus on the effective application of military power and include aspects like focus, unity of command, and maneuver, among others.

"Economy of Force" emphasizes allocating minimal essential combat power to secondary efforts, ensuring that maximum resources are focused on the main effort. "Objective" refers to directing military actions toward a clearly defined goal, which is vital for maintaining operational efficiency and effectiveness. "Simplicity" advocates for straightforward plans to reduce confusion and increase the likelihood of success during complex operations. Each of these principles is integral to achieving success in joint operations, highlighting their importance in military doctrine.

On the other hand, while "Legitimacy" is an important consideration in military operations—contributing to factors such as public support and international law—it does not formally appear among the core principles that guide joint operational strategy. This distinction is crucial for understanding the framework within which military leaders operate and plan their missions.