The assistant secretary of defense for international security affairs (ASD (ISA)) is responsible for international security strategy, defense policy, and oversight of security cooperation programs and foreign military sales programs relating to Europe, the North Atlantic Treaty Organization, Russia, Eurasia, the Middle East, Africa, and the Western Hemisphere.

The assistant secretary of defense for special operations/low-intensity conflict (ASD(SO/LIC)) is responsible for the policy, resources, strategic capabilities and force transformation, and oversight of special operations and low-intensity conflict matters of the United States Department of Defense across counterterrorism, unconventional warfare, direct action, special reconnaissance, foreign internal defense, civil affairs, information and psychological operations, and counterproliferation of weapons of mass destruction.

The director of the Defense POW/MIA Accounting Agency is responsible for the personnel recovery of United States Department of Defense personnel who are listed as prisoners of war (POW) or missing in action (MIA), from all past wars and conflicts around the world.

The Principal Deputy Under Secretary of Defense for Policy is the chief staff assistant to the USD(P).

102–190), the post was re-designated Principal Deputy Under Secretary of Defense (Policy), or PDUSD(P) in December 1999 by DoD Directive 5111.3.