Airmen with the Japan Air Self-Defense Force operate a reverse osmosis water purification unit during Silver Flag Dec. 6, 2016, at Northwest Field, Guam. Silver Flag is a U.S. Pacific Command multilateral subject matter expert exchange led by engineers from the 554th RED HORSE Squadron. The exercise is designed to build partnerships and promote interoperability through the equitable exchange of civil engineer-related information. (U.S. Air Force photo by Senior Airman Arielle K. Vasquez/Released)