U.S. Marines with the 1st Battalion, 1st Marine Regiment are transported on an MV-22 Osprey tiltrotor aircraft assigned to Marine Medium Tiltrotor Squadron (VMM) 161 to an urban operations town while conducting a helicopter insertion to nighttime urban terrain raid training Feb. 18, 2014, during Iron Fist 2014 at Camp Pendleton, Calif. Iron Fist is a three-week bilateral training event held annually between the U.S. Marine Corps and the Japan Ground Self-Defense Force designed to increase interoperability between the two services while aiding the Japanese in their continued development of amphibious capabilities.