Japan Ground Self-Defense Force (JGSDF) soldiers jump into a pool to conduct casualty drills during a helocast preparation exercise at Marine Corps Base Camp Pendleton, Calif., Jan. 28, 2012. The event was part of exercise Iron Fist 2012, a three-week bilateral training event held annually between the U.S. Marine Corps and the JGSDF designed to increase interoperability between the two services while aiding the Japanese in their continued development of amphibious capabilities.