First Lt. Jonathan Loper, a KC-135 Stratotanker pilot with the 465th Air Refueling Squadron, Tinker Air Force Base, Okla., reviews flight brief material during Rim of the Pacific exercise, Joint Base Pearl Harbor-Hickam, Hawaii, July 26, 2012. Twenty-two nations, more than 40 ships and submarines, more than 200 aircraft and 25,000 personnel are in RIMPAC exercise from June 29 to Aug. 3, in and around the Hawaiian Islands. The world's largest international maritime exercise, RIMPAC provides a unique training opportunity that helps participants foster and sustain the cooperative relationships that are critical to ensuring the safety of sea lanes and security on the world's oceans. RIMPAC 2012 is the 23rd exercise in the series that began in 1971.