What principle ensures that all military operations are directed towards a clearly defined and attainable objective?

The principle that ensures all military operations are directed towards a clearly defined and attainable objective is the concept of "Objective." This principle emphasizes the importance of having a specific aim that guides all planning and actions. It ensures that resources and efforts are concentrated toward achieving that goal, thus increasing the effectiveness and efficiency of operations.

By maintaining a clear objective, military commanders can align their strategies, allocate resources appropriately, and assess their success based on whether they are moving closer to that defined target. This clarity helps minimize confusion and allows for coordinated efforts across various units and functions within the operation.

In contrast, the other principles mentioned serve different purposes within military strategy. The offensive principle focuses on the initiative in operations, the economy of force principle relates to the efficient use of resources, and perseverance emphasizes the importance of sustaining efforts throughout the course of an operation. Each of these aspects plays a crucial role in military strategy, but it is the "Objective" principle that ensures all efforts are purposefully directed toward a specific, attainable goal.