Which of the following is NOT a responsibility of the Secretary of the Army?

The responsibility of directing Navy operations does not fall under the purview of the Secretary of the Army. The Secretary of the Army is primarily focused on managing the Army's operations, resources, and personnel. This role includes overseeing Army-specific missions, strategic planning, and ensuring that the Army is effectively resourced and staffed to fulfill its commitments.

In contrast, directing Navy operations is the domain of the Secretary of the Navy, who handles all matters related to the Navy and its operations. As a distinct branch of the U.S. military, the Navy operates independently from the Army, even though both are under the Department of Defense.

The other responsibilities, such as oversight of operations, managing resources, and personnel management, are indeed key roles of the Secretary of the Army. These duties ensure that the Army remains operationally ready and effective in carrying out its missions.