Summary: Pursuant to a congressional request, GAO reviewed current and future Department of Defense (DOD) war reserve materiel requirements. GAO noted that: (1) DOD war reserves are used to support military units during wartime; (2) DOD distributes war reserves to military units on an as needed basis and stores reserves in prepositioned areas near potential conflicts; (3) prepositioned equipment is mostly stored in central Europe and is configured to support deploying combat units; (4) afloat prepositioning involves keeping ships continuously loaded with supplies, combat equipment, and support items and is intended to respond to crises more quickly than continental U.S. deployment; (5) DOD war reserve requirements are expected to continue to decline because of strategic changes and force reductions; (6) the amount of prepositioned equipment on hand for the Army's current brigade requirements may increase if current land and afloat prepositioning requirements are filled entirely; and (7) the Army's plan to preposition two of its nine brigade units to southwest Asia would reduce some DOD sealift requirements and negate the need to move some brigade units from the continental United States.