Final answer:
The SECDEF is tasked with the regular review of the U.S. national defense strategy and related policies, but the specific frequency is not detailed in the provided information. These reviews ensure military preparedness, manage a large defense budget, and uphold the U.S.'s numerous defense agreements globally.
Step-by-step explanation:
The Secretary of Defense (SECDEF) is responsible for ensuring the United States is adequately prepared for defense and foreign policy issues. It is part of their duties to conduct a comprehensive examination of the national defense strategy, including aspects such as force structure, modernization plans, infrastructure, budget plan, and other elements of the defense program and policies on a regular basis. However, the specific frequency of these examinations is not detailed in the provided information. The examination is crucial for the development and maintenance of the U.S.'s foreign policies and to manage its military commitments, which include defense agreements with 37 countries, more than 700 military installations abroad, and an annual defense budget of around $1.3 trillion.
Traditionally, military strength forms the central pillar of national security policies. Since the National Security Act of 1947, the various branches of the U.S. military, like the Army, Navy, Marine Corps, and Air Force, are overseen by the Department of Defense to ensure the U.S. is capable of mounting a strong military offense and defense. This continuous preparedness and policy evaluation are vital for the U.S. to fulfill its international obligations and safeguard national interests.