U.S. Army Lt. Col. Victor R. Sarkozi, left, the deputy commander for Opposition Forces (OPFOR) for Yama Sakura (YS) 65, speaks with Japanese OPFOR personnel at Camp Higashi-Chitose, Japan, Dec. 8, 2013. YS is an annual, bilateral exercise between the U.S. military and the Japan Self-Defense Forces. YS is the largest command post exercise that focuses predominantly on the bilateral and joint planning, coordination and interoperability of ground-based elements of the U.S./Japan security alliance.