Charles Nicholls, Pacific Air Forces historian, gives a history tour to senior leaders of the Sri Lanka air force at Headquarters PACAF, Joint Base Pearl Harbor-Hickam, Hawaii, Aug. 22, 2019. During the four-day visit, SLAF and U.S. Air Force senior leaders engaged in three different working groups; humanitarian assistance and disaster relief, air and maritime domain awareness, and force development. (U.S. Air Force photo by Staff Sgt. Mikaley Kline)